Keep satellite gateway service alive during a session

Bug: 275633844
Test: Call/SMS/MMS with live network. Wil add a mock satellite gate service for testing in CTS.
atest android.telephony.cts.SatelliteManagerTest
atest com.android.internal.telephony.satellite.SatelliteSessionControllerTest

Change-Id: I8e1ce8e9b3af675d350a14ae950b81506988436e