Modify error handling for registerForNtnSignalSterngthChanged API

Throws exception instead of returning error.

Bug: 306111250
Test: atest SatelliteControllerTest, SatelliteManagerTest, SatelliteManagerTestOnMockService
Change-Id: I4342e51ed3f9dbf5fdef77d8f018f3513d1a0a3b
1 file changed