[automerger skipped] [ DO NOT MERGE ] libhwc2.1: change mPowerModeState as optional am: 08d70c8f0f am: c257b4761e -s ours

am skip reason: subject contains skip directive

Original change: https://googleplex-android-review.googlesource.com/c/platform/hardware/google/graphics/zuma/+/19851870

Change-Id: I6ebca4a7094168ad9b8692ff989efbbd7eb7b64e
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>