Merge branch '20.0.x' into mkirkova/fix-16162-20.0.x

Author: RivaIvanova

projects/igniteui-angular/src/lib/grids/tree-grid/tree-grid.component.html

@@ -3,7 +3,6 @@
 <igx-grid-header-row class="igx-grid-thead" tabindex="0"
     [grid]="this"
     [hasMRL]="hasColumnLayouts"
-    [activeDescendant]="activeDescendant"
     [width]="calcWidth"
     [pinnedColumnCollection]="pinnedColumns"
     [unpinnedColumnCollection]="unpinnedColumns"