Analysis: Resolve on loading changed deprecation warn on media preview

Warning Message: "Overrides deprecated method in
'com.google.android.exoplayer2.Player.Listener'"

Explanation: "Use onIsLoadingChanged(boolean) instead."

For more info see:
- exoplayer2.Player.Listener#onIsLoadingChanged (Doc):
https://exoplayer.dev/doc/reference/com/google/android/exoplayer2/
Player.Listener.html#onIsLoadingChanged(boolean)

WordPress/src/main/java/org/wordpress/android/ui/media/MediaPreviewFragment.java

@@ -330,7 +330,8 @@ boolean showAudioOrVideo() {
     }
 
     private class PlayerEventListener implements Player.Listener {
-        @Override public void onLoadingChanged(boolean isLoading) {
+        @Override
+        public void onIsLoadingChanged(boolean isLoading) {
             showProgress(isLoading);
         }
     }