Bluetooth: A2DP offload HIDL

Interface for Bluetooth A2DP offload feature.

Bug: 63932139
Bug: 72242910
Test: Manual; TestTracker/148125
Change-Id: I3649800dfe3e1a2d66b76859be87e01ee58d2de0
(cherry picked from commit 4e95d81ef048bfdc33cee7cf8bdbe66603b30f96)
7 files changed