Change variables to atomic variables.

Following variables are converted to atomic variables:
- mNtnSmsSupportedByMessagesApp
- mIsWifiConnected
- mHasSentBroadcast
- mSatelliteModemState

Bug: 409608013
Test: atest
Flag: com.android.internal.telephony.flags.satellite_improve_multi_thread_design
Change-Id: I86029af167c342db19cea7d960faa16fd564fa4a