Merge "Guard against missing mac addresses in onWakeupEvent" into udc-dev am: 34f6424c51

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/22880033

Change-Id: Ibe6f5a4dbf5ef6ca2bfd7469a6406e2d2721b528
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>