initializeUiControllerMixin method
Must be Called -----------------------------------------------------------
Implementation
@visibleForOverriding
Future<void> initializeUiControllerMixin() async {
VolumeController.instance.showSystemUI = false;
VolumeController.instance.isMuted().then((value) => _isMuted = value);
VolumeController.instance.getVolume().then((value) => _volume = value);
_nowPlaying.addListener(_prepareThumbnailPreviews);
}