CarrierServiceStateTracker: Solve problems with dual sim

Solves problems with notifications in CarrierServiceStateTracker that
occur in dual sim scenario:

-Lets each subscription publish its notification with a unique
notification id. This prevents a race condition where notifications from
different subscription compete whether the notification should be
shown or hidden.

-Considers subId when loading string resources. This ensures that
the correct string resources will be loaded if it has been configured by
an operator.

Bug: 129289303
Test: atest FrameworksTelephonyTests
Change-Id: Id0b2fe0b808ab62c3c6c94581935456bad35898a