fix(android): do not require java 8 target

Updates react-native-webrtc to get rid of Java 8 requirement for
the Android app.

android/README.md

 `https://github.com/jitsi/jitsi-maven-repository/raw/master/releases` and the
 dependency `org.jitsi.react:jitsi-meet-sdk:1.9.0` into your `build.gradle`.
 
-Add Java 1.8 compatibility support to your project by adding the following lines
-into your `build.gradle` file:
-
-```
-compileOptions {
-    sourceCompatibility JavaVersion.VERSION_1_8
-    targetCompatibility JavaVersion.VERSION_1_8
-}
-```
-
 ## API
 
 Jitsi Meet SDK is an Android library which embodies the whole Jitsi Meet

android/app/build.gradle

             proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
         }
     }
-    compileOptions {
-        sourceCompatibility JavaVersion.VERSION_1_8
-        targetCompatibility JavaVersion.VERSION_1_8
-    }
 }
 
 dependencies {

package-lock.json

       }
     },
     "react-native-webrtc": {
-      "version": "github:jitsi/react-native-webrtc#7e54c61679f5a3d1ca5dcdf598f7a7c31f94a0bd",
+      "version": "github:jitsi/react-native-webrtc#626818af40384356617f70366133317b6a475171",
       "requires": {
         "base64-js": "1.2.3",
         "event-target-shim": "1.1.1",

package.json

     "react-native-locale-detector": "github:jitsi/react-native-locale-detector#cc76092fc4335488a28a9529c8b50afae2c3ecdc",
     "react-native-prompt": "1.0.0",
     "react-native-vector-icons": "4.4.2",
-    "react-native-webrtc": "github:jitsi/react-native-webrtc#7e54c61679f5a3d1ca5dcdf598f7a7c31f94a0bd",
+    "react-native-webrtc": "github:jitsi/react-native-webrtc#626818af40384356617f70366133317b6a475171",
     "react-redux": "5.0.6",
     "redux": "3.7.2",
     "redux-thunk": "2.2.0",

react/features/base/lib-jitsi-meet/native/RTCPeerConnection.js

         afterCallbacks: number) {
     return function(...args) {
         return new Promise((resolve, reject) => {
-
             if (args.length <= beforeCallbacks + afterCallbacks) {
                 args.splice(beforeCallbacks, 0, resolve, reject);
             }