In case an application gets disabled the level is set to "experimental" if it does not contain a `shipped` tag. This can for example be reproduced by installing the documents app from the appstore and then disabling it. Or cloning an app from git.
With this change the controller will now load the level of the application from the appstore if a valid OCSID has been provided.
Fixes https://github.com/owncloud/core/issues/17003
