Changed API name from 'isNtn()' to 'isOnlyNonTerrestrialNetwork()' and updated related methods and variables according to API Council recommendations.

isNtn() -> isOnlyNonTerrestrialNetwork()
No changes in logic.

Bug: 301620244
Test: PreferredSimDialogFragmentTest SimListDialogFragmentTest
Change-Id: I2b64262ed4d9f81f830f76b10a2174ad1e1d649f
5 files changed