Do not show context menu for videos

app/src/common/shared/org/mozilla/vrbrowser/ui/widgets/WindowWidget.java

@@ -1454,6 +1454,9 @@ private void hideContextMenus() {
 
     @Override
     public void onContextMenu(GeckoSession session, int screenX, int screenY, ContextElement element) {
+        if (element.type == ContextElement.TYPE_VIDEO) {
+            return;
+        }
         TelemetryWrapper.longPressContextMenuEvent();
 
         hideContextMenus();