[ECM] Create EnhancedConfirmationService

This change:

1. Defines EnhancedConfirmationService, a new SystemService
2. Defines IEnhancedConfirmationManager, a new binder interface
   implemented within EnhancedConfirmationService
3. Injects EnhancedConfirmationService into EnhancedConfirmationManager
4. Moves the bulk of EnhancedConfirmationManager's logic into
   EnhancedConfirmationService

Bug: 321053639
Test: atest CtsPermissionUiTestCases:android.permissionui.cts.EnhancedConfirmationManagerTest
Change-Id: Ib6fbf4dde07391314bfd2a64f22bab79a6cebd23