Add Firefox Android (Fenix) 79.0 (#6586)
Add Firefox Android (Fenix) 79.0 (#6586)

Release notes: https://support.mozilla.org/en-US/kb/whats-new-firefox-android-79
chrisdavidmills/browser-compat-data,chrisdavidmills/browser-compat-data,mdn/browser-compat-data,mdn/browser-compat-data