Steps to reproduce:

1. Login to backoffice.
2. Go to Admin / Content Types / Content.
3. Create new content and add at least one Field definition e.g. 'Authors'.
4. Clear all the inputs from the form and click on 'Discard changes' button.

Actual result:

See attachment and watch gif please: https://recordit.co/OZMCuKICD7

User cannot discard changes until required fields are not filled.

Expected result:

User can discard changes without fill out required fields.

Comment:

The validation error doesn't appear while user is trying to create a content type without filled out required fields (see attachment or watch gif).

Bug related with this task: https://jira.ez.no/browse/EZP-31849