Issue Summary

Iframe macro allows you to embed content into Confluence pages, such as Google Sheets, GoogleDocs, etc.
However, it doesn't allow you to embed google drive files. 
It says 403 Forbidden.

Steps to Reproduce

1. Upload a video (.mov) or a PDF file to Google Drive
2. Create a page 
3. Add an iframe macro to the Confluence page
4. Copy the link from the uploaded file in Google Drive
5. Paste the link in the iFrame macro
6. Confirm it "loaded" in the macro by seeing it on the page
7. Publish the page

Expected Results

Google Drive Files loads the file, the same way it works with Google Spreadsheets and Google Docs.

Actual Results

Google Drive Files does not load in the iFrame, it returns a 403 error Forbidden instead.

content-security-policy-report-only: require-trusted-types-for 'script' https://csp.withgoogle.com/csp/docs-tt   

Workaround

Try using the Google Embedded option from the SmartLink cards in the current editor (does not work with the Legacy editor).
Just copying the link from the Google Drive file and pasting it on the page will make the SmartLink card appear.
Click on the card and choose an embedded option.