playAudioAsset method
Implementation
@override
Future<FutureOr<void>> playAudioAsset(String assetPath) async {
final bytes = await rootBundle.load("assets/$assetPath");
final file = File('${(await getTemporaryDirectory()).path}/$assetPath');
await file.create(recursive: true);
await file.writeAsBytes(bytes.buffer.asUint8List());
methodChannel.invokeMethod('playAudioAsset', {'uri': file.uri.path});
}