Merge pull request #15199 from edx/ammar/edu-211-html5-player-overlay-play-button

common/lib/xmodule/xmodule/css/video/display.scss

common/lib/xmodule/xmodule/js/fixtures/video.html

common/lib/xmodule/xmodule/js/fixtures/video_all.html

common/lib/xmodule/xmodule/js/fixtures/video_hls.html

common/lib/xmodule/xmodule/js/fixtures/video_html5.html

...on/lib/xmodule/xmodule/js/fixtures/video_no_captions.html

...on/lib/xmodule/xmodule/js/fixtures/video_with_bumper.html

...on/lib/xmodule/xmodule/js/fixtures/video_yt_multiple.html

...on/lib/xmodule/xmodule/js/spec/video/video_player_spec.js

common/lib/xmodule/xmodule/js/src/video/02_html5_video.js

lms/templates/video.html