Merge "Mark several NetworkAgentInfo members @NonNull and address TODO." am: 61209f8504 am: 72dbdf2cdf am: 9f864e3e5b

Original change: https://android-review.googlesource.com/c/platform/frameworks/base/+/1552502

MUST ONLY BE SUBMITTED BY AUTOMERGER

Change-Id: I3d6b833342292026f5f0a91a96006ece31762b9a