aaudio test: fix looping multiple times using -l

Wait for stream to pause before flushing.
Remove scary -110 result message.

Bug: 68271891
Test: adb shell write_sine_callback -pl -m2 -n2 -s2 -c2 -l100
Change-Id: Ide7e7642cbe0b9d43023106a526e8f1e205aab77
Merged-In: Ide7e7642cbe0b9d43023106a526e8f1e205aab77