[automerger skipped] Tighten ART's OWNERS file. am: 8ef9529cb9 -s ours

am skip reason: Merged-In I928ab19e413c35611e9f9c97948c21af5f7b44e2 with SHA-1 3362cf159a is already in history

Original change: https://googleplex-android-review.googlesource.com/c/platform/art/+/15241580

Change-Id: I0afd1e59fa60d9c587cfcdb926130902ef136079