Revert "hal: Fix for no audio on BT headset till waiting call is ended."

This reverts commit cf6a0ac452ee433da6b73e1934ecde8012f0a13d. This is to
fix isInCall() to return proper value.

CRs-Fixed: 740052
Change-Id: Iee7fb448df7f5f428b2011a996b6b97e5488d245
Merge "Revert "hal: Fix for no audio on BT headset till waiting call is ended.""
Merge feed9ef395a9807f799a0484a2e6c4dbcc4ebff6 on remote branch

Change-Id: I103d8edc2e83798abe553ea1cd528f169cece05b
Merge "Merge feed9ef395a9807f799a0484a2e6c4dbcc4ebff6 on remote branch"