HFPClient connectAudio

According to the Bluetooth HFP specification it is the responsibility of
the AG (Phone) to connect audio upon answering a call.  Removing the
call running on the HF to prevent possible race conditions.

Bug: 113977380
Test: Place and answer calls, observe BT logs.
Change-Id: I03ab601f8b255c535ce436b52ee42fa4693ded4f