Inconsistency on formatPermission on nuxeo-format-behavior master vs 10.10

The function formatPermission on nuxeo-format-behavior has different outcomes on master and 10.10 branch when the permission doesn't have a label. In master it returns the key in lowercase, whereas in 10.10 returns the key as is.

Reproduction: 

On https://preview-coldstorage-master.napps.dev.nuxeo.com/

Navigate to a document, then go to a documents permission tab, click on add new local permission. In the Right dropdown, if the permission doesn't have a label, it will show its key in lowercase, such as writeColdStorage