JSC wasn't the cause for the crash we were hunting after all. RN doesn't set
HErmes as the default, neither does Expo, so the jury is still out on Hermes,
and it looks like JSC is still the safest bet.

In addition, the way Hermes is packaged (as a standalone AARs, instead of a
local "Maven repo") complicates the SDK build and can make the resulting build
bloated.

Android < 23 is currently less than 3% for us so let's try to lower the
maintenance burden. Users can still download an older version no problem.

This will be mandatory later in the year for updating apps and it already is for
new apps.

https://support.google.com/googleplay/android-developer/answer/113469#targetsdk

It can now be automated in a CI environment as follows:

yes | sdkmanager --licenses

A libre build will exclude the following:

- Analytics modules
- Google Play services GMS
- Crashlytics
- Firebase

- don't hardcode defaults in gradle files
- allow for uploading also to HTTP URLs
- support HTTP authentication when publishing

Use an ever increasing number so no manual updates are necessary.

This new version comes with an updated JSC runtime, so we no longer need to
depend on the updated version ourselves.

They generate a bunch of harmless yet confusing error messages and they are not
really useful.

This is done at the app level, not the SDK.

Currently 2 Firebase services are used:

  - Crashlytics
  - Dynamic Links

They are enabled in tandem, if the appropriate Google services file
(GoogleService-Info.plist on iOS or google-services.json on Android) is found.

Each service needs to be individually enabled in the Firebase console.

Note that Android 9 Pie (API 28) disallows HTTP requests by default, so an
exception was needed in the app in order for the Metro bundler to work in debug
mode.

The Google repository is already added with google().

Glide (which is used by react-native-fast-image) can cause trouble if the host
app (the one using the SDK) is using Glide already.

To avoid this, don't use the builtin AppGlideModule (as the docs recommend) and
let apps define it.

Every time the android version that is used changes we need to update the license hash.

The dependency was dropped, so it's no longer needed.

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

The JSC version used by React Native is about 3 years old, and doesn't implement
things like Symbol or Typed Arrays, which require polyfills. These polyfills are
sometimes a los less performant, as is the case for Typed Arrays.

Bumping an updated JSC version makes both platforms consistent when it comes to
the JavaScript platform.

Releases are also published to jcenter, and due to how the dependency is
declared, we are picking the latest release from there, which is arguably not
what we want.

Also remove mavenLocal since we don't need it.

Android Oreo (API level 26) is supported since React Native 50.

Android Studio won't build the app otherwise. Since the gradle plugin 3.0 beta7,
the minimum supported build tools version is 26.0.2, so set it to that. Also
bump compileSdkVersion to 26 since they need to match (in the major number, that
is).

The target API is still 25. Android Oreo (26) brought some changes in overlay
permissions which I haven't figured out yet.