resumePlayer method
Resume the current playback.
An exception is thrown if the player is not in the "paused" state.
Return
Returns a Future which is completed when the function is done
Example
await myPlayer.resumePlayer();
See also
Implementation
Future<void> resumePlayer() async {
  _logger.d('FS:---> resumePlayer');
  await _lock.synchronized(() async {
    await _resumePlayer();
  });
  _logger.d('FS:<--- resumePlayer');
}