Don't ever report a null ServiceState

Report out of service if we don't know any better.  Sometimes when switching radios
we were finding nulls reported - it crashed some code and highlighted this problem.
If we don't have a service state we're certainly out of service, so this isn't a lie.

bug:4553701
Change-Id: I094798a5f9f39f45c0ba30179aaa8f88f9b3e405