Remove akersten from OWNERS am: b978aa3d67 am: e4e0ebfa95

Original change: https://android-review.googlesource.com/c/platform/packages/apps/UniversalMediaPlayer/+/1526880

MUST ONLY BE SUBMITTED BY AUTOMERGER

Change-Id: I46d52b31f5a20aa4e3247b2948e3288d841271a8