Add HAL interface to replace aaudio system property.

Using the HAL interface instead of reading system property is a better
option when moving to AIDL HAL. The replaced property includes:
  - aaudio.mixer_bursts
  - aaudio.hw_burst_min_usec

Test: atest AAudioTests
Bug: 193275465
Change-Id: I9c9a04296e56ff083babcfa089fcdddc6b89ed94