AudioFlinger: Extract inner Track classes

Finish removing inner Track classes from AudioFlinger.

Test: atest audiorecord_tests audiotrack_tests audiorouting_tests trackplayerbase_tests audiosystem_tests
Test: atest AudioTrackTest AudioRecordTest
Test: YouTube and Camera
Bug: 288339104
Bug: 288468076
Merged-In: Ib44c7eb854f9d447aa11223d76373b00c413a778
Change-Id: Ib44c7eb854f9d447aa11223d76373b00c413a778
13 files changed