dispose method
Dispose a video player
Implementation
@override
Future<void> dispose(int textureId) async {
final playerId = _textureIdToPlayerId[textureId];
if (playerId == null) return;
final controller = _controllers.remove(playerId);
if (controller != null) {
await controller.dispose();
}
_valueControllers.remove(playerId)?.close();
_textureIdToPlayerId.remove(textureId);
}