[automerger skipped] Implement alternate power button behavior for dreams. am: bffe18bf28 am: 95ba64e23f -s ours

am skip reason: Merged-In I9b6859b4933839841b76b832f275dcc14313f192 with SHA-1 7012ed5a09 is already in history

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/20132039

Change-Id: I0574450c90469f9835d91b818d9a695727b7fd6d
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>