Merge pull request #11544 from pedrobmarin/guest-doorbell

...button-html5/imports/ui/components/settings/component.jsx

...i/components/settings/submenus/notification/component.jsx

...5/imports/ui/components/waiting-users/alert/component.jsx

bigbluebutton-html5/private/config/settings.yml

bigbluebutton-html5/private/locales/en.json

bigbluebutton-html5/public/resources/sounds/doorbell.mp3