Modify error handling for registerForNtnSignalStrength

Return value of registerForNtnSignalStrengthChanged become void from int.
Throws RemoteException which wraps SatelliteException includes
SatelliteResult, when registration operation fails.

Bug: 306111250
Test: atest SatelliteControllerTest, SatelliteManagerTest, SatelliteManagerTestOnMockService
Change-Id: I2a7fa65204a102584e12622b8f92dedc68a384a8