Query Apn protocol by roaming state

The roaming network protocol may be different than home network
protocol, select the correct protocol by roaming state.
Besides, carrier configuration may override the framework
roaming state, we should use the actual modem roaming state.

Bug: 110315058
Test: SUPL test on roaming Fi network and home network

Change-Id: Ie132b98dea25fd9762da793ada0543dccb9701e9