Bluetooth: Check A2dp device priority.

For incoming connections stack does not check priority
of device.Add support to check priority of device in stack
for incoming connection.

Change-Id: Icc78d22048800bd448a93f96ab31e2673ce28dca
CRs-Fixed: 510957
Merge branch 'cm-11.0' of https://github.com/CyanogenMod/android_hardware_libhardware into cm-11.0