Audio : Fix a few minor issues with stream switcher class am: 035beba2 am:...

Audio : Fix a few minor issues with stream switcher class am: 035beba2 am: f901f6a4 am: e54466ff

Original change: https://android-review.googlesource.com/c/platform/hardware/interfaces/+/2680756



Change-Id: I70d9e49ccb9430a283acd9b501f78737193847aa
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>