Fix commands
Fix commands

the gcloud `app` commands while now in public beta are still under the preview commands, even in the newest available release.
dart-lang/appengine,exitlive/appengine,dart-lang/appengine,kevmoo/appengine,kevmoo/appengine,kevmoo/appengine,kevmoo/appengine,exitlive/appengine,exitlive/appengine