Resume FM on telephony idle state

If volume button pressed while call is ringing, FM receives AUDIOFOCUS.
On call termination, FM don't resume, as FM already received
AUDIOFOCUS and don't resume FM on call termination.
Hence turn on FM when telephony CALL_IDLE_STATE intent received.

Change-Id: Ib38e4f622d57ead0c7a97a241280c9c9db57da8d