audio service: fix BT SCO intent permission
audio service: fix BT SCO intent permission

Clear calling identity before calling BluetoothHeadset
methods from binder call.
Also send BT SCO audio state intents from the
message handler, not from binder calls.

Bug 8242429

Change-Id: I742ba8dc47a258dbee6fb9d57db302f2bffaafd7

xorware/android_frameworks_base,xorware/android_frameworks_base,xorware/android_frameworks_base,xorware/android_frameworks_base,xorware/android_frameworks_base,xorware/android_frameworks_base