aaudio test: add close option to test_steal_exclusive

This can be used to simulate apps that fail to close the stream
when it is disconnected.

Test: adb root
Test: adb remount -R
Test: mmm frameworks/av/media/libaaudio/tests/
Test: adb push $OUT/data/nativetest64/test_steal_exclusive/test_steal_exclusive /system/bin/.
Test: test_steal_exclusive -c0   # do NOT close
Test: test_steal_exclusive -c1   # close enabled
Bug: 199285450
Change-Id: I0930eda1c8e2258b22f71d786c7b3d092cf4daa4