Toggle FM on receiving AVRCP play command

While FM is playing over BT and press the play/pause button from BT
headset, receiving the AVRCP play command from BT headset. On receving AVRCP
play command from BT headset, if FM is already on, we don't turn off the FM and
FM keeps playing.
Toggle the FM to on/off on receving the play command.

Change-Id: Iee34ca9d40929a0f5fd04fcfba0c42f29a0dd388