AudioTrack offload: fix EVENT_STREAM_END not called

If the track thread is paused, EVENT_STREAM_END will not delivered
 for offload. This event is required for PRESENTATION_END to
 be delivered for Java AudioTrack offload.

Bug: 86837964
Test: cts-tradefed run cts -m CtsMediaTestCases -t android.media.cts.AudioTrackOffloadTest

Change-Id: I491cdb0a6faa69e5c37139c0364b5c9079ff1f14