[backend] Adjust state changing services to unset `auto_resolved` boolean flag

Why are we doing this work?

After we [backend] Add `auto_resolved` boolean for Vulne... (#493862 - closed) we must ensure that changing the state to anything else than resolved will unset the auto_resolved boolean flag

Implementation plan

1. Unset auto_resolved in ee/app/services/vulnerabilities/{dismiss,confirm,revert_to_detected}_service.rb