audio: Add 'Void' AIDL type am: b31baae920 am: e929a0f1ad

Original change: https://android-review.googlesource.com/c/platform/system/hardware/interfaces/+/2296540

Change-Id: I72e3f55dca8115662af69e30d3c784e85a57ae50
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>