When the user is having connectivity issues we use the image cached in
the video element to show the preview in greyscale. It looks like this
cached image gets invalided after prolonged periods of time the video
element being hidden(and it is hidden when the video is muted). So we
never show this image if the user gets muted during connectivity
disruption in order to avoid blackness.

We used to rely on 'currentTime' of the video element, but we execute
'updateView' from the 'onplay' callback and on fast machines it may
happen that the value is 0 even though the video has just started.

At any point of time we display one of the three: video, avatar or
blackness. The purpose of this commit is to make that fact more clear
in the code.

The video or the avatar on a thumbnail will be displayed in greyscale
when the user is having connectivity issues.

This reverts commit 76a7c7b426.

There was a bug that the handlers for menuItem for mute and kick are added for all remote participants. When clicked multiple handlers are executed and the action will be executed for all remote participants.

Handles the case where the remote track is with initial value of camera and no further events are received for video type changed.

Commented part seems not to be required anymore as everything work well without it.

Removes duplicated logic for hiding video element when the user is muted.