Use bugfix workflow for clear strong auth change

* Change the flag's name to reset the workflow
* Mark it as a bugfix

Bug: 320817991
Test: atest FrameworksServicesTests:LockSettingsServiceTests
Flag: android.security.clear_strong_auth_on_adding_primary_credential
Change-Id: If61f2ca2ed353474a1e2453e4e63e8c32d47fe7c