chore(android): improve exoplayer logs (#3780)

* 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: improve issue template

* fix(android): avoid video view flickering at playback startup

* fix: improve debuging display and enable it in the sample

android/src/main/java/com/brentvatne/exoplayer/ReactExoplayerViewManager.java

@@ -448,6 +448,7 @@ public class ReactExoplayerViewManager extends ViewGroupManager<ReactExoplayerVi
         } else {
             DebugLog.setConfig(Log.WARN, enableThreadDebug);
         }
+        videoView.setDebug(enableDebug);
     }
 
     private boolean startsWithValidScheme(String uriString) {