Handle multi party call states

UseCase:
1. Set up Bluetooth connection between phone and remote device.
2. Disconnect BT link by turning off remote device.
3. Start Mo call from phone.
4. Receive MT call from far end.
5. Turn on remote device.
6. BT connection gets established successfully, but audio
doesn't get transferred to headset.

Failure:
Call audio not routed to BT HS. SCO not established.

Root cause:
When a HS connects while in an active call and 2nd call
(incoming/outgoing/alerting) setup ongoing, incorrect post SLC
call setup updates might cause HS to get confused as phone had
already updated correct call states in CIND response during SLC.
This may cause HS to behave abnormally like delayed response to
BCS as seen with jabra wave +.

Fix:
Avoid sending incorrect call updates post SLC since we already
have sent correct updates during SLC as reponse to CIND.

Change-Id: I53e57baf7cca782af6f374a043667971c66a956d