powerstats: add OWNERS for power stats am: 7885d61cd4 am: 6230c14fe5 am: 03bc2cf0c1

Original change: https://android-review.googlesource.com/c/device/google/gs-common/+/2375575

Change-Id: If023c632ae81e0fe56381d6c70b70433781a87ab
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>