Provide a way to require Creative Commons license in submission form

[wvalmorbida]

Describe the bug I need the Creative Commons step to be required in submission process. I tried changing "mandatory" to "true" in step definitions (item-submission.xml) but it didn't work.

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To Reproduce

1. Change configuration "mandatory" to "true"
2. Restart tomcat
3. Start new submission
4. Fill all required fields, except cc license
5. Submit submission
6. Done, but shouldn't

Expected behavior Expected that form validation does not allow the submission to be submitted