[Sb refactor] Proper support for carrierNetworkChangeMode

Testing via demo mode exposed that `carrierNetworkChangeMode` was not
suppored in the SignalIconModel, only in calculating `roaming`. This
change adds support to:

1. Draw the "marching dots" UI properly when in carrier network change
   mode
2. Ignore any network data type icon when the mode is active

Test: SignalIconModelParameterizedTest
Test: MobileIconViewModelTest
Bug: 284967021
Change-Id: Ieb740ceb0bfc1a8dd6c853d048a15c48775085c7