chore(android): refactor side loaded text tracks (#3754)

* perf: ensure we do not provide callback to native if no callback provided from app

* chore: rework bufferConfig to make it more generic and reduce ReactExoplayerView code size

* chore(android): refactor external text tracks management.

Split parsing and tracks handling

* chore: fix linter

android/src/main/java/com/brentvatne/exoplayer/VideoPlaybackService.kt

@@ -72,9 +72,7 @@ class VideoPlaybackService : MediaSessionService() {
 
     // Callbacks
 
-    override fun onGetSession(controllerInfo: MediaSession.ControllerInfo): MediaSession? {
-        return null
-    }
+    override fun onGetSession(controllerInfo: MediaSession.ControllerInfo): MediaSession? = null
 
     override fun onBind(intent: Intent?): IBinder {
         super.onBind(intent)