The MOBILE_MMS, MOBILE_SUPL, MOBILE_DUN and MOBILE_HIPRI net types used
by location, messaging, and vending needed to be exposed.
Bug: 2363272
Change-ID: I6d2361d3642064db619b283b9217512563eb3439
Mark cellular variants with the same availability, regardless of which are currently in use.
Availability just means the radio is enabled and sees the network, but has no guarantees that
we could connect to an APN if requested.
Fix the requestRouteToHost logic to support apn switches without WIFI.
bug:2093841
This also refactors ConnectivityService a bit towards supporting multiple simultaneous connections by making each a seem like a seperate Network with it's own stateTracker, etc.
Also adds tracking of process death to clean orphaned startUsingNetworkFeature features.
