When uploading a document that corresponds to a specific document type, the user is given the option to translate it into different languages. The default language of the document will always be the default language of the site; however, the UI misleads users into thinking that they can set the default language for each document by including a "Change" button next to the default language which brings up a drop-down language selection menu when clicked.
This issue does not occur in 7.1 or above because
LPS-78974 adds a new translation UI that fixes the issue in those versions. However, this new UI is not feasible to backport. We should do a unique fix for 7.0.x.
Steps to Reproduce
1. Start a clean bundle of Liferay 7.0 and log in as the admin user
2. Navigate to Content -> Documents and Media and add a document of type Marketing Banner
3. Upload a file.
4. Try to edit the default language to something other than English.
Expected Result: The UI should not allow you to edit the default language to something other than English because the default language of the document will always be the Site default, which is English.
Actual Result: The UI allows you to edit the default language to something other than English. However, if you save the document and then go to edit again, you will see that the default langue is still English. This is a misleading UI.