Change carrier name shown No Service to ECO

In the case where at least one SIM supports EC (either it has service or
it supports them), we replace "No service" carrier name into "Emergency calls
only". This does not replace the string if the sub is already mark as
ECO.

Test: manual
Test: atest KeyguardUpdateMonitorTest
Test: atest CarrierTextControllerTest
Fixes: 130857483
Fixes: 133201131
Fixes: 132291669
Change-Id: Ia0ba2076c9750a8bb081994291753dbea68a2270