Add onCarrierRoamingNtnEligibleStateChanged callback.

Mark a phone object as carrier roaming ntn eligible if:
- Phone supports P2P SMS over satellite
- Device is not connected to Wi-Fi
- Phone is OUT_OF_SERVICE

Moved isCellularAvailable() from SatelliteSOSMessageRecommender to
SatelliteServiceUtils so that it can be used easily by other classes.

Bug: 350396906
Test: atest SatelliteControllerTest, atest DefaultPhontNotifierTest,
atest TelephonyRegistryTest, atest TelephonyCountryDetectorTest, atest
SatelliteServiceUtilsTest
Manual Test: b/353971031
Flag: com.android.internal.telephony.flags.carrier_roaming_nb_iot_ntn

Change-Id: I2b9e8d90147d6751092e63b27131ee00ffbe7b08