[automerger skipped] Add CTS for registerBestMatchingNetworkCallback am: 512efafd32 -s ours am: eb50be9103 -s ours

am skip reason: Merged-In I81abc1742a3aa965b444d0196f4eaa2393dcad1c with SHA-1 512efafd32 is already in history

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/modules/Connectivity/+/14673220

Change-Id: Icb7cacf12d3f2000b650b7f993a4e89af46c4b07