Merge "add metrics for notification and group expansion" into nyc-dev
am: 0f97b8fcbd

* commit '0f97b8fcbddbbd40f5cf45ba57a5d9db48a611a0':
  add metrics for notification and group expansion

Change-Id: I32d730fcc03da49217d9c4ba2a27f41e15eca73f