Merge "Use registerSystemDefaultNetworkCallback to listen underlying network" am: 817021b9b7 am: a196c820e8

Original change: https://android-review.googlesource.com/c/platform/frameworks/base/+/2183584

Change-Id: I0a97e67c618d8de34eb7f1225347c62625befdf1
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>