Merge "Use registerSystemDefaultNetworkCallback to listen underlying network" am: 817021b9b7 am: a196c820e8 am: 433eeb633b

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

Change-Id: I476141b4dcbea2e0148b28475d1162db04a510c4
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>