Shows react-native-track-player incorrectly resetting playback rate in some circumstances

After cloning repo, pod install within the ios directory. Then open ios/TrackPlayerRateTest.xcworkspace, build, and run.

1. Click Toggle Rate so that the playback rate goes to 2
2. Click Play to start listening to some fast audio
3. Now click Forward 15s

You'll notice the playback rate goes back to 1.0.

It turns out the following sequence is problematic:

  await TrackPlayer.setRate(2);
  await TrackPlayer.play();
  await TrackPlayer.seekTo(position + 15);
  await TrackPlayer.play();

Specifically, if you seek while playing, and then call play() in the new position, it'll reset the playback rate. I've not debugged into SwiftAudioEx enough to figure out the cause, but this is at least a reliable repro.