Preview tab not showing for restricted files even though user has permission to access

[mdmADA]

What steps does it take to reproduce the issue?

1. Install and enable a previewer.
2. Create dataset with one or more restricted files.
3. Grant permission to a user to one or more restricted file.
4. User logs in and navigates to the dataset
5. User sees Preview 'eye' icon in the Files list for the restricted file they have access to
6. User clicks the 'eye'
7. the file.xhtml page is rendered for the user
8. there is no Preview tab

• When does this issue occur?
  Only for restricted files

• Which page(s) does it occurs on?
  In every dataset page when a Previewer is enabled.

• What happens?
  See above ^^^
  It happens because FilePage.java calls FileUtil.isPreviewAllowed() which returns false if the file is restricted (and does not check if the user actually has access). FilePage should call FileDownloadHelper isPreviewAllowed() as that is the method called by all other classes/objects and allows the eye icon to show in the files list in the first place.

• To whom does it occur (all users, curators, superusers)?
  Anyone who has access through a role.

• What did you expect to happen?
  The preview tab in the file.xhtml should show.

Which version of Dataverse are you using?
This will occur for every version of dataverse since the file previewers were created. I tested it on demo.dataverse.org v5.8

Any related open or closed issues to this bug report?

Screenshots:

See the Dataverse Users Community conversation with Phil: https://groups.google.com/g/dataverse-community/c/kjhzKAuncSs
for screenshots

[mdmADA]

Note that I only tested it with SpreadsheetPreviewer but given the restricted file condition returning false in the FileUtil.isPreviewAllowed() method, I expect the issue is across all previewers.