Allow Bluetooth CAP_SYS_NICE, set RT priority for Bluetooth HAL

Bluetooth needs CAP_SYS_NICE in order to make important threads use RT
scheduling policy.

SchedulingPolicyService should set RT priority for the Bluetooth HAL.

Bug 37518404

Test: Play Bluetooth audio, confirm RT priority in systrace
Change-Id: I0ee55a2f2cfd80cbb066d9c034bb85d8d85ba470
2 files changed