Make reportInetCondition revalidate if the report differs from our state

1. If reportInetCondition says the network is not working, and
   the network is already marked not validated, don't revalidate
   it. This was superfluous and should save battery.
2. If reportInetCondition says the network is working, and the
   network is not marked as validated, revalidated. This will
   allow us to get out of a validated state quickly based on app
   input (e.g., allowing GCM's exponential backoff timer to drive
   revalidation instead of our 10-minute timer).

Bug: 19258761
Bug: 19209043
Change-Id: Iaa4bac82d117ed1f4088dab106e6f6ce46b34bc3