Merge "Correct nullability and add extra check for underpinnedNetwork" am: e932d646b3

Original change: https://android-review.googlesource.com/c/platform/packages/modules/Connectivity/+/2483815

Change-Id: I0410ae73a24bceb0c7f8b4280e4121a71b07c9a3
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>