[FEATURE REQUEST] Flag to prevent download or streaming of videos on start

[jvenki]

Is your feature request related to a problem? Please describe.
Even though there is a flag to disable autoPlay, I believe the video is gettig downloaded in the background. I have 100s of videos rendered on a screen and the view becomes unresponsive at start. Is there a way I prevent download of videos till they are PLAYED.

Describe the solution you'd like
I would like a flag to control this behaviour of downloading videos. It makes sense when there is only 1 video that we are downloading and keeping it ready. Not really required when the page has many videos. Therefore I would recommend having a flag to disable download just like autoPlay.

Describe alternatives you've considered
A clear and concise description of any alternative solutions or features you've considered.

Additional context
I did come across #569, but not sure how to use it.

[jvenki]

Is the expectation that we have to invoke YoutubePlayer.getThumbnail without building YoutubePlayer. On click on the image, we then insert the YoutubePlayer into the widget tree?