Merge "Improve RouterAdvertisementDaemonTest." am: 662237f2f8 am: 3b2ad2b764 am: b8aa244e11

Original change: https://android-review.googlesource.com/c/platform/packages/modules/Connectivity/+/1669025

Change-Id: If6f9a6f06c38c75282660334d5b39153c13dbb5b