Don't use APNs xml if CarrierSettings is installed

If the CarrierSettings app is installed then we don't need to insert the
APNs from the xml file on boot or update. When restoring APNs we bind to
a service specified in resources and then block until restored.

Bug: 37283190
Test: manual and existing unit test passes
Change-Id: I7d41bc331bdfffe582f7d57dee2b237fa2b83144
Merged-In: I7d41bc331bdfffe582f7d57dee2b237fa2b83144
2 files changed