Switch makefile owners to MK_OWNERS am: 231936b1b3

Original change: https://android-review.googlesource.com/c/device/google/tangorpro/+/3107877

Change-Id: I78065e3350668512f0a3ba527897f58805a603a0
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>