Description:

I am getting the error related to content security policy after uploading a custom emoji -> I think it's causing thumbnail is not rendered

Steps to reproduce:

1. Sign in as an admin user
2. Go to Administration >> Custom Emoji
3. Click + button to add a custom emoji
4. Upload an image with .png format
5. Observe the emoji thumbnail after uploaded

Expected behavior:

Thumbnail of emoji should be loaded

Actual behavior:

Thumbnail of emoji is not loaded

Relevant info:

https://app.birdeatsbug.com/sessions/Ha1EWvkklqDHvN6-PPVVh?