Don't unnecessarily reevaluate tethering provisioning

Registering for carrier config changes can deliver a sticky broadcast
and can cause Tethering to think something has changed and reevaluate
provisioning status, even though this has been checked before it
entered tethering mode alive state.

Additionally, move the provisioning_app{,no_ui} resources into the
TetheringConfiguration, if for no other reason than now we can log
it in .toString().

Test: as follows
    - built
    - flashed
    - booted
    - runtest frameworks-net passes
    - manual USB tethering toward WiFi works
Bug: 69565814
Merged-In: If254326e892b78ef9daf620f829c1def136d695c
Merged-In: I288093a1d76566e72d4889d92c7aedafc318c8b6

Change-Id: I01c71fd971a4683bb2b6d14825d36f24a04d88a8