chore(*): Update test with timeout for requestAnimation addition to autosize.

Author: skrustev

projects/igniteui-angular/src/lib/grids/pivot-grid/pivot-grid.spec.ts

@@ -1938,7 +1938,7 @@ describe('IgxPivotGrid #pivotGrid', () => {
                 expect(pivotGrid.rowDimensionWidthToPixels(rowDimension)).toBe(158);
             });
 
-            it('should auto-size row dimension when width is set to auto.', () => {
+            it('should auto-size row dimension when width is set to auto.', fakeAsync(() => {
                 const pivotGrid = fixture.componentInstance.pivotGrid;
                 let rowDimension = pivotGrid.pivotConfiguration.rows[0];
                 expect(rowDimension.width).toBeUndefined();
@@ -1976,11 +1976,12 @@ describe('IgxPivotGrid #pivotGrid', () => {
                 };
 
                 fixture.detectChanges();
+                tick(200);
                 rowDimension = pivotGrid.pivotConfiguration.rows[0];
                 expect(rowDimension.autoWidth).toBe(158);
                 expect(rowDimension.width).toBe('auto');
                 expect(pivotGrid.rowDimensionWidthToPixels(rowDimension)).toBe(158);
-            });
+            }));
 
             it('should auto-generate pivot config when autoGenerateConfig is set to true.', () => {
                 const pivotGrid = fixture.componentInstance.pivotGrid;