SF: Do not deref empty std::optional<PowerMode> am: e63a592135

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/native/+/20553509

Change-Id: Ia1cb6c874ce7af08113839c9150d371b7dec1b89
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>