Media copy pasted from external private source show as “preview unavailable"

Issue Summary

This is reproducible on Data Center: No

The bug affects all the users trying to copy/paste images from a private source to create an issue using the new issue-create experience. This also happens while pasting a file to the comments of an existing issue.

Steps to Reproduce

1. Send email to yourself using Gmail web and attach picture in-line
2. Open email and copy an image from your private Gmail account using your keyboard.
3. Paste that image in the issue description
4. Create the issue or paste the content in the comment of an existing issue

Additional information:

• If email you are pasting pics from has pictures loaded via external links (e.g. mail list) then picture will be attached properly to the issue.
• If email has private pics attached to the email (e.g. you receive email with pic attached), then the issue is reproducible.

Expected Results

The image should be visible to all the users who have access to view the issue.

Actual Results

The image is only visible to the users who have access to view the source files. The other users see a Preview unavailable thumbnail.

Workaround

You can download the file and then use the "Files & images" button in the editor toolbar to upload the media.