AutoPauseAndResumeMediaPlayer property

If this prop (can be set in AndroidGameActivity) be true, then the
AndroidGamePlatform will automatically pause and resume the MediaPlayer
on activation and deactivation of game (also corrects the behavior so
that on activation MediaPlayer will resume if on deactivation it has
been playing)
and if this prop set to be false, then the behavior will be handled by
user code manually (we use this in our game)