[Status bar refactor] Add Roaming to the mobile pipeline

Copied the logic exactly as it is from the old pipeline. Roaming is
defined as:

True if (!carrierNetworkChange && ((isGsm && serviceState.roaming) ||
(!isGsm && getCdmaEnhancedRoamingIndicatorDisplayNumber != ERI_OFF)))

Test: MobileConnectionRepositoryTest
Test: DemoMobileConnectionsRepositoryTest
Test: MobileIconInteractorTest
Test: MobileIconViewModelTest
Test: manual in demo mode
Bug: 238425913
Change-Id: If8b9b46e44175c9865ad396023f9f5e49b2105a8