AudioFlinger: Add MmapThread interfaces

Add IAfMmapThread, IAfMmapCaptureThread, IAfMmapPlaybackThread

Test: atest audiorecord_tests audiotrack_tests audiorouting_tests trackplayerbase_tests audiosystem_tests
Test: atest AAudioTests AudioTrackOffloadTest
Test: atest AudioTrackTest AudioRecordTest
Test: YouTube Camera
Bug: 288339104
Bug: 289233517
Merged-In: Icb348a4affdb6c41fd6bfa4270933d0a9ac281d9
Change-Id: Icb348a4affdb6c41fd6bfa4270933d0a9ac281d9
5 files changed