Check isInCarrierRoamingNbIotNtn for the phone associated with SmsDispatchersController object

FLAG: com.android.internal.telephony.flags.carrier_roaming_nb_iot_ntn 
Bug: 369502538
Test: atest GsmSmsDispatcherTest ImsSmsDispatcherTest CdmaSmsDispatcherTest SmsDispatchersControllerTest
Manually test send P2P SMS over NTN using test app

Change-Id: I4f0e0e4cb3719a5a43d43607e4a68e298ef38574