Prefer SIM carrier name over network carrier

People generally identify their SIMs by the emitting carrier, not
the network they attach to. In roaming or MVNO scenarios, these
are likely not to be the same, leading to confusion in SIM selection.

Ref CYNGNOS-2496

Change-Id: I0ecd8e7511fd4229d6ce7629b1f97aa83a1a6254