Upload a new version of a file in the legacy editor doesn't generate a new token

Issue Summary

When previewing a file in the legacy editor, using the Upload a new version to upload a new file may throw a "Your session has expired. You may need to re-submit the form or reload the page." error if the atl.xrsf.token is missing.

Steps to Reproduce

1. Create a page in the legacy editor and upload a document file (pdf, docx, xlsx...)
2. Publish the page
3. Delete all the cookies and login again or delete only the atl.xrsf.token one through the browser's developer tools
   (although this has happened naturally to some users, without the need to manually delete the cookies/ token)
4. Open the file for preview and use the Upload a new version button to upload a new file

Expected Results

It should successfully upload the file

Actual Results

The following error might happen:

"Your session has expired. You may need to re-submit the form or reload the page."

The following video better shows the issue happening:

• session_expired.mp4

Workaround

The available workaround is to upload the file using drag-and-drop while viewing the page:

• workaround.mp4