Switch makefile owners to MK_OWNERS am: 973d618f32

Original change: https://android-review.googlesource.com/c/device/google/gs101/+/3107248

Change-Id: Ib07243ecf056f8a9f525933d0fa7f3a13eb9a0a3
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>