Add a mechanism for Audio Feeding Parameters negotiation

Previously, the Audio Feeding Parameters between the Media Framework
and A2DP were hard-coded: 44.1 KHz sample rate, 16-bits per sample, Stereo.
Now the Media Framework queries A2DP, and uses the returned values.

Bug: b/30958229
Test: Manual testing: A2DP streaming to headphones. TestTracker/68727
Change-Id: I70b90d2961ceb9efcd7021d2e12c240fe531ee1c