Merge changes Iadf7f15d,I74702938,Ib8a725cd into nyc-mr2-dev

* changes:
  DO NOT MERGE Network notifications: revamp keying scheme
  DO NOT MERGE Define Network notification proto constants.
  DO NOT MERGE Unit tests for NetworkNotificationManager
tree: faad6e9b73a9997a5ee5b4f154836fdb3e7b7c49
  1. core/
  2. services/
  3. tests/