Fix video swap when there's no presentation and/or screenshare/external video

...ton-html5/imports/ui/components/actions-bar/component.jsx

...ton-html5/imports/ui/components/actions-bar/container.jsx

...s/ui/components/external-video-player/modal/component.jsx

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

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