Stabilize audio playback types used by the HAL

The following types used to be framework-only (belonging
to android.media package). Since they need to be used
by the HAL, move them to stable android.media.audio.common
types package:
  - AudioDualMonoMode
  - LatencyMode -> AudioLatencyMode
  - AudioPlaybackRate

Bug: 175167149
Bug: 205884982
Test: m
Change-Id: I6cbe34d3b343fbefb0ae56e00dbf8360184e7b72
Merged-In: I6cbe34d3b343fbefb0ae56e00dbf8360184e7b72