aaudio test: flushing to start transition

Add test for state transitions from FLUSHING to STARTED,
FLUSHING to CLOSING, etc.

Also test for CLOSING to STARTED, STOPPED, etc.

This is to test a regression in R.

Bug: 158603375
Bug: 159900922
Test: this is a test
Change-Id: Idce40ad28d21438973facd9f32ef59e47c463279