audio: add OWNERS for the README.md am: 6a9f697dfe

Original change: https://android-review.googlesource.com/c/platform/hardware/interfaces/+/2169871

Change-Id: Ica3988cec6c7540ecc96206972ee192a514ce301
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>