fix(igxGrid): Make throttle emit last value as well.

Author: MKirova

projects/igniteui-angular/src/lib/directives/for-of/for_of.directive.ts

@@ -404,7 +404,8 @@ export class IgxForOfDirective<T> implements OnInit, OnChanges, DoCheck, OnDestr
             });
             const destructor = takeUntil<any>(this.destroy$);
             this.contentResizeNotify.pipe(destructor,
-            filter(() => this.igxForContainerSize && this.igxForOf && this.igxForOf.length > 0), throttleTime(40))
+            filter(() => this.igxForContainerSize && this.igxForOf && this.igxForOf.length > 0),
+             throttleTime(40, undefined, {leading: true, trailing: true}))
             .subscribe(() => {
                 this._zone.runTask(() => {
                     this.updateSizes();