Adds a config for trusted accessibility services.

Any service which is both preinstalled and on this list does not
require a warning dialog to be shown to the user.

New feature flag:
adb shell device_config override accessibility android.view.accessibility.skip_accessibility_warning_dialog_for_trusted_services true

Depends on existing feature flag:
adb shell device_config override accessibility android.view.accessibility.cleanup_accessibility_warning_dialog true

Bug: 303511250
Test: atest AccessibilityManagerServiceTest
Test: Populate the list with component names;
      Open Settings > Accessibility;
      Enable a service on the list: no warning dialog
      Enable a service not on the list: warning dialog
Change-Id: I49e5d33dd43212d8b73d3225ad668a804554f54d