BT: Multi HF support in Bluetooth App.

1. Added support for Multi HF connections
in Bluetooth application.
2. All connection transition states for
2nd HS onwards is handled in new state-
MultiHFPending.
3. The changes are done to handle proper
state transition for all connected HS.

Conflicts:

	src/com/android/bluetooth/hfp/HeadsetStateMachine.java

Change-Id: I64f06bf925ce92ce2822eb524551acef279b627f