[ICON REQUEST]: Firefox (updated)

### I have searched through the issues and didn't find my problem.

- [x] Confirm

### About the icon

Already in project

### Links and sources

The current Firefox logo is very outdated. Here is the new logo:

https://en.wikipedia.org/wiki/Firefox_logo#/media/File:Firefox_logo,_2019.svg

### Icon links and previews

### Additional information

Permission details:

https://hg.mozilla.org/mozilla-central/file/c75d6a0539eb4b2c7961f0c9782fcb364198c6b2/browser/branding/official/LICENSE