Merge changes Ib9dde023,I917506fc,I8576cc36 into udc-dev

* changes:
  [SB Refactor] Only use carrier merged sub ID if wifi or CM are default.
  [SB Refactor] Use a real WifiRepo in MobileConnectionsRepositoryTest.
  [SB Refactor] Convert MobileConnectionsRepositoryTest to testScope etc.