Init the mediaplayer with a sound resource id

Property definitions

android $ MediaPlayer :: from_id
	# Init the mediaplayer with a sound resource id
	init from_id(context: NativeActivity, id: Int) do
		self.nmedia_player = new NativeMediaPlayer.create(context, id)
		if self.nmedia_player.is_java_null then
			self.error = new Error("Failed to create the MediaPlayer")
			self.sound = new Music.priv_init(id, self, self.error)
		end
		self.sound = new Music.priv_init(id, self, null)
	end
lib/android/audio.nit:383,2--391,4