Merge "DHCPv4: lease expiration is fatal, renew failures are not" into nyc-dev am: 42a5755916
am: 81092a2de8

* commit '81092a2de8d6d2cd003a88ed9dc991fa7dd0350d':

Change-Id: Id68aa8f81f11042c7583fad42da2063cbb17efe1