Fix EmergencyAffordanceService

Significantly rework Emergency Affordance Service.

-Enable country-by-country behavior based on ISO not MCC.
-Rely on LocaleTracker for the cellular network country.
-Remove all locking/synchronization.

Bug: 130187110
Test: com.android.server.emergency.EmergencyAffordanceServiceTest
Test: Feature regression test located at go/EAS-regression
Change-Id: I66315988b14d7cbdb5278a1006327818dc5ab11e