Merge "audio: Make StreamDescriptor::Command a union" am: 2b68543625

Original change: https://android-review.googlesource.com/c/platform/hardware/interfaces/+/2296167

Change-Id: Ica626ce3d3ea5c3be78efcf5f6e64724a9263c7a
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>