Replace ECM AppOps call with service

A new ECM service was introcuded in changeId
I831391e4437b51b3312b5273a2360bd029a3d8ee.

We begin calling it, and update/cleanup method signatures to match.

Note: There are two feature flags:

1. enhancedConfirmationModeApisEnabled - read only, protects the
   mainline API.

2. extendEcmToAllSettings - runtime - gates calls to the above APIs.

We use both so we can ramp up in teamfood as needed.

Bug: 297372999
Test: Tested on device
Test: atest SpaPrivilegedLibTests
Test: atest com.android.settings.applications.specialaccess.notificationaccess
Test: atest com.android.settings.datausage
Test: atest PremiumSmsAccessTest
Test: atest RestrictedPreferenceHelperTest
Change-Id: I4125e71078a1a06e954bfc317c344e1016406ffb