Merge changes I37ab7767,I13890cdc,Idd5fa020,I6f614d61 into tm-qpr-dev

* changes:
  [SB refactor] Wire up DataConnectionState to the view model
  [SB refactor] Add connectivity tracking to the mobile pipeline
  [SB refactor] Upgrade most data sources to `StateFlow`
  [SB refactor] Track the default subscription and its connection status