BLD-915: Fix issues with different videoIDs.

CHANGELOG.rst

common/djangoapps/terrain/start_stubs.py

common/djangoapps/terrain/stubs/youtube.py

common/lib/xmodule/xmodule/js/spec/video/initialize_spec.js

...n/lib/xmodule/xmodule/js/spec/video/video_caption_spec.js

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

common/lib/xmodule/xmodule/js/src/video/01_initialize.js

common/lib/xmodule/xmodule/js/src/video/03_video_player.js

.../xmodule/xmodule/js/src/video/06_video_progress_slider.js

common/lib/xmodule/xmodule/js/src/video/09_video_caption.js

common/test/data/uploads/subs_b7xgknqkQk8.srt.sjson

lms/djangoapps/courseware/features/video.feature

lms/djangoapps/courseware/features/video.py