fix(tile-view) fix screensharing size in self view (#10634)

clean-up overriden css for tileview video tags

css/filmstrip/_tile_view.scss

@@ -99,19 +99,6 @@
                 display: block;
                 margin: 2px;
             }
-
-            video {
-                object-fit: contain;
-            }
-
-            /**
-            * Max-width corresponding to the ASPECT_RATIO_BREAKPOINT from features/filmstrip/constants.
-            */
-            @media only screen and (max-width: 500px) {
-                video {
-                    object-fit: cover;
-                }
-            }
         }
     }
 }

react/features/filmstrip/components/web/Thumbnail.js

@@ -479,17 +479,18 @@ class Thumbnail extends Component<Props, State> {
         }
 
         let videoStyles = null;
+        const doNotStretchVideo = (_height < 320 && tileViewActive)
+            || _disableTileEnlargement
+            || _isScreenSharing;
 
-        if (!_isScreenSharing) {
-            if (canPlayEventReceived || _participant.local) {
-                videoStyles = {
-                    objectFit: (_height < 320 && tileViewActive) || _disableTileEnlargement ? 'contain' : 'cover'
-                };
-            } else {
-                videoStyles = {
-                    display: 'none'
-                };
-            }
+        if (canPlayEventReceived || _participant.local) {
+            videoStyles = {
+                objectFit: doNotStretchVideo ? 'contain' : 'cover'
+            };
+        } else {
+            videoStyles = {
+                display: 'none'
+            };
         }
 
         styles = {