fix(tile-view): thumbnail videos should cover entire thumbnail
fix(tile-view): thumbnail videos should cover entire thumbnail

Video elements may have problems scaling to cover pixel fractions,
so there could be a 1px black border line displaying in the
thumbnail. It's most visible in tile view. Flooring the sizing
calculations hides the border.

jitsi/jitsi-meet,bgrozev/jitsi-meet,gpolitis/jitsi-meet,gpolitis/jitsi-meet,bgrozev/jitsi-meet,gpolitis/jitsi-meet,gpolitis/jitsi-meet,gpolitis/jitsi-meet,gpolitis/jitsi-meet,jitsi/jitsi-meet,jitsi/jitsi-meet,bgrozev/jitsi-meet,bgrozev/jitsi-meet,bgrozev/jitsi-meet,gpolitis/jitsi-meet,jitsi/jitsi-meet,jitsi/jitsi-meet,bgrozev/jitsi-meet,gpolitis/jitsi-meet,jitsi/jitsi-meet,jitsi/jitsi-meet,jitsi/jitsi-meet