audio: Fix AudioTrack stuck while interrupting waitStreamEndDone

When AudioTrack is waiting for waitStreamEndDone() and there is interrupt coming.
There is timing issue that AudioTrack will not enter STATE_STOPPED and be stuck at
requestExitAndWait().
Move interrupt after exit flag be set to prevent this problem.

Bug: 208191856
Test: atest CtsMediaTestCases
Change-Id: I2a42b99ae4d33ff95db2a736585475b4ee636d04