Provide a default and builtin default implementation which finishes the
Activity, same as before.

What this PR removes is the ability to provide a custom default handler because
applications can already take this decision when calling `onBackPressed`. In
addition, make `onBackPressed` return `void` because it's virtually impossible
for it to return `false` (that would mean that there is no
`ReactInstanceManager`, which means there is no app to begin with).

In addition, remove the use of `BackAndroid` since `BackHandler` contains an iOS
shim now.

Assume it's at the same level as the Jitsi Meet repo, by default.

Set them to the next release versions. In additon, the buildNumber variable will
be used to match the requirements of versionCode:
https://developer.android.com/studio/publish/versioning

that is, a monotonically increasing number, independent of the app / sdk
version.

The upstream package has been unmaintained for 2 years now, and making the litle
changes needed as React Native needs them is getting old. The actual
funcionality is a couple of one-liners plus tons of boliterplate, which gets
reduced by quite a bit if we just embed it. So here it goes.

Due to a switch to a newer version of JSCore, the jsc-android dependency is now used by the
SDK. As this dependency is not (yet) available in the Jitsi Maven repository, an error like
this is reported when an application is ran that uses the SDK:

    com.facebook.react.common.JavascriptException: Can't find variable: Symbol

This commit primarily improves the instructions on how to create a local Maven repository
that contains all required dependencies, including the JSCore dependency that was missing.

This intends to address the issue described in https://github.com/jitsi/jitsi-meet/issues/3399

Since this is a feature implemented in the SDK, it makes sense that all the
plumbing required to make it work it's in the SDK itself.

This makes the PermissionsAndroid builtin module work.

Introduce the JitsiMeetActivityInterface, which defines the interface that
activities using JitsiMeetView directly must implement in order to ensure full
functionality.

Use react-native-fastimage, which uses 2 full-native image impleentations using
well known and mature (native) libraries.

This gets us rid of 2 libraries which were observerd as a source of bugs and
created trouble with dependencies: react-native-fetch-blob and
react-native-img-cache. They are also no longer well maintained.

It's a separate view (on the native side) and app (on the JavaScript side) so
applications can use it independently.

Co-authored-by: Shuai Li <sli@atlassian.com>
Co-authored-by: Pawel Domas <pawel.domas@jitsi.org>

As the need for adding more views connected with our React code arises, having
everything in JitsiMeetView is not going to scale.

In order to pave the way for multiple apps / views feeding off the React side,
the following changes have been made:

- All base functionality related to creating a ReactRootView and layout are now
  in BaseReactView
- All Activity lifecycle methods that need to be called by any activity holding
  a BaseReactView are now conveniently placed in ReactActivityLifecycleAdapter
- ExternalAPIModule has been refactored to cater for multiple views: events are
  delivered to views, and its their resposibility to deal with them
- Following on the previous point, ListenerUtils is a utility class for helping
  with the translation from events into listener methods

* feat(recording): add sounds for when recording starts and stops

* squash: use constants, play sounds for file only

* squash: rename recordingStopped.mp3 -> recordingOff.mp3

* squash: flip var declaration for alpha order

The API to gather these was introduced in API level 26.

Activity.enterPictureInPictureMode method must be invoked synchronously
on userLeaveHint callback in order to be sure that the current Activity
is still visible (does not transit to PAUSED state). Previously if the
asynchronous processing would be delayed enough for the Activity to go
into the PAUSED state it will be too late to go into the PiP mode.

* Button conditionally shown based on if the feature is enabled and available
* Hooks for launching the invite UI (delegates to the native layer)
* Hooks for using the search and dial out checks from the native layer (calls back into JS)
* Hooks for handling sending invites and passing any failures back to the native layer
* Android and iOS handling for those hooks

Author: Ryan Peck <rpeck@atlassian.com>
Author: Eric Brynsvold <ebrynsvold@atlassian.com>

Activity.enterPictureInPictureMode can fail for a couple of reasons
mentioned in the JSDoc:

"The system may disallow entering picture-in-picture in various cases,
including when the activity is not visible, if the screen is locked or
if the user has an activity pinned."

It seems to be safe to assume that those cases will be caught by
a RuntimeException handler (only RuntimeExceptions can be left without
explicit catch block).

Anyway the root cause for problems is the fact that the current process
for going to the picture in picture mode is not synchronised with
Activity's lifecycle. On Activity's "userLeaveHint" callback we dispatch
async task to the JS code which only then after dispatching some more
stuff eventually call native method that enter PiP. In case we spend too
much time on the JS side and the Activity goes to PAUSED state the call
will fail with IllegalStatException: "activity is not visible",
"activity is paused" etc. This means with this fix the app will not
crash, but we'll see it sometimes not go to the PiP mode as expected.

On Android the files will be copied to the assets/sounds directory of
the SDK bundle on build time. To play the "asset:/" prefix has to be
used to locate the files correctly.

On iOS each sound file must be added to the SDK's Xcode project in order
to be bundled correctly. To playback we need to know the path of the SDK
bundle which is now exposed by the AppInfo iOS module.

Adds Nat64InfoModule which resolves IPv6 addresses for IPv4 addresses
in IPv6 only network where jitsi-meet deployment does not provide any
IPv6 addresses as ICE candidates.

Adds base/sounds feature which allows other features to register a sound
source under specified id. A new SoundsCollection component will then
render corresponding HTMLAudioElement for each such sound. Once "setRef"
callback is called by the HTMLAudioElement, this element will be added
to the Redux store. When that happens sound can be played through the
new 'playSound' action which will call play() method on the stored
HTMLAudioElement instance.

java.lang.RuntimeException: Tried to access a JS module before the React instance was fully set up. Calls to ReactContext#getJSModule should only happen once initialize() has been called on your native module.
	at com.facebook.react.bridge.ReactContext.getJSModule(ReactContext.java:102)
	at com.rnimmersive.RNImmersiveModule.emitImmersiveStateChangeEvent(RNImmersiveModule.java:74)
	at org.jitsi.meet.sdk.JitsiMeetView.onWindowFocusChanged(JitsiMeetView.java:504)
	at android.view.View.dispatchWindowFocusChanged(View.java:10257)
	at android.view.ViewGroup.dispatchWindowFocusChanged(ViewGroup.java:1193)
	at android.view.ViewGroup.dispatchWindowFocusChanged(ViewGroup.java:1197)
	at android.view.ViewGroup.dispatchWindowFocusChanged(ViewGroup.java:1197)
	at android.view.ViewGroup.dispatchWindowFocusChanged(ViewGroup.java:1197)
	at android.view.ViewGroup.dispatchWindowFocusChanged(ViewGroup.java:1197)
	at android.view.ViewGroup.dispatchWindowFocusChanged(ViewGroup.java:1197)
	at android.view.ViewGroup.dispatchWindowFocusChanged(ViewGroup.java:1197)
	at android.view.ViewRootImpl$ViewRootHandler.handleMessage(ViewRootImpl.java:3602)
	at android.os.Handler.dispatchMessage(Handler.java:102)
	at android.os.Looper.loop(Looper.java:154)
	at android.app.ActivityThread.main(ActivityThread.java:6119)
	at java.lang.reflect.Method.invoke(Native Method)
	at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:886)
	at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:776)

This only works automatically on Android >= 8. On other platforms / versions, it
relies on the SDK user on implementing a "reduced UI" mode and reacting to the
"request PIP" delegate method.

On Android we go into "immersive mode" when in a conference, this is our way of
being full-creen. There are occasions, however, in which Android takes us out of
immerfive mode without us (the application / SDK) knowing: when a child activity
is started, a modal window shown, etc.

In order to be resilient to any possible change in the immersive mode, register
a listener which will be called when Android changes it, so we can re-eavluate
if we need it and thus re-enable it.

The documentation states this is possible, so make sure we handle such errors.

Ref:
https://developer.android.com/reference/android/provider/Settings.html#ACTION_APPLICATION_DETAILS_SETTINGS