Check if the NTN is connected or not and change the signal threshold criteria.

Listen for service state changes.
If the service state changes between NTN and TN, change the signal threshold criteria.

Bug: 311272134
Test: atest SignalStrengthTest, atest SignalStrengthControllerTest
Test: manual test.
After NTN is connected,
1. verify SMS working.
2. verify Voice call and Internet blocked.
3. verify whether the NTN_LTE signal thresholds config is used.

Change-Id: If68a693347c0d5c8b03d6f8a707754be67d4935f