audio: add OWNERS for the README.md am: 6a9f697dfe am: c812fbf2c6

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

Change-Id: Ief6d413fac4a56e23bf935b762760531f9957ff6
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>