Merge branch 'v2.0.x-release' into sfu-opt-audio

...ton-html5/imports/api/users/server/methods/userLeaving.js

.../imports/ui/components/audio/audio-controls/component.jsx

...ml5/imports/ui/components/audio/audio-modal/component.jsx

...luebutton-html5/imports/ui/components/audio/container.jsx

bigbluebutton-html5/imports/ui/components/audio/service.js

...ml5/imports/ui/components/notifications-bar/container.jsx

...luebutton-html5/imports/ui/components/toast/container.jsx

...uebutton-html5/imports/ui/services/audio-manager/index.js