Map DcConstants.RETRYING to PhoneConstants.State.DISCONNECTED.

Previously RETRYING was mapped to CONNECTING this means that
ConnectivityService will not remove the route and a subsequent
change in IP addresses won't work because an old route has not
been removed.

By mapping to DISCONNECTED ConnectivityService will remove the
route. Another alternative would be to add PhoneConstants.State.RETRYING
but this is a simpler change so we'll try it first.

Bug: 8486114
Change-Id: I1c9946a1e441feda83f13730e835445624a87218