Remove mitchp from OWNERS am: cea50c9a35 am: 807b201e0d

Original change: https://android-review.googlesource.com/c/device/google/gs-common/+/3321033

Change-Id: I18642110a1acdd8b02bd0613cd2805359a34cdbf
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>