hal: Add support for speaker safe and BT A2DP usecases

Add backend configuration in audio HAL for speaker safe and
BT A2DP usecases.

Bug: 79873626
Test: play ringtone with BT A2DP headset connected
Change-Id: I2a14098a1f1d812e48dda48c4e46c4663362e7fe
5 files changed
tree: 95cfc96539c21a15c4801cb70a0b20617b47659d
  1. hal/
  2. legacy/
  3. post_proc/
  4. visualizer/
  5. voice_processing/
  6. Android.mk