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

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

MUST ONLY BE SUBMITTED BY AUTOMERGER

Change-Id: I07fa9035369c8abde6de395b21630b239bdd4247