Main Video and Thumbnail Videos are flickering

[ok2ju]

Main Video and Thumbnail Videos re-renders (flickering) after active speaker selection, also when actionBar appearing.

Steps to reproduce:

1. Open two instances of app in different tabs (so in the same room should be two users, or more);
2. Click on one of Thumbnail video to select active speaker;

Actual result: Main Video element and Thumbnail Videos are flickering (coz fully re-render);
Expected result: Main and Thumbnail Videos should not flickering.