Revert "Revert "Complete hard removal of BluetoothHeadset#setPri..."

Revert "Revert "Hard remove BluetoothHeadset#setPriority System ..."

Revert "Revert "Added removal of BluetoothHeadset#setPriority to..."

Revert submission 16433519-hfp-setpriority-hardremove

Tag: #feature
Bug: 209335798
Test: Manual
Reason for revert: CTS issue fixed
Reverted Changes:
I9de1b07f2:Revert "Complete hard removal of BluetoothHeadset#...
If5d408e8b:Revert "Added removal of BluetoothHeadset#setPrior...
I3c717fad0:Revert "Hard remove BluetoothHeadset#setPriority S...

Change-Id: Id86ba6bd922cd862560a635cc9b8bd79ca0f9d28