Revert "fix(autocomplete): auto-highlighted first option not display correctly if the floating label is disabled"

src/lib/autocomplete/autocomplete-trigger.ts

@@ -493,7 +493,6 @@ export class MatAutocompleteTrigger implements ControlValueAccessor, OnDestroy {
         switchMap(() => {
           this._resetActiveItem();
           this.autocomplete._setVisibility();
-          this._changeDetectorRef.detectChanges();
 
           if (this.panelOpen) {
             this._overlayRef!.updatePosition();

src/lib/autocomplete/autocomplete.spec.ts

@@ -1644,22 +1644,6 @@ describe('MatAutocomplete', () => {
           .toContain('mat-active', 'Expected first option to be highlighted.');
     }));
 
-    it('should be able to preselect the first option when the floating label is disabled',
-      fakeAsync(() => {
-        fixture.componentInstance.floatLabel = 'never';
-        fixture.componentInstance.trigger.autocomplete.autoActiveFirstOption = true;
-        fixture.detectChanges();
-
-        fixture.componentInstance.trigger.openPanel();
-        fixture.detectChanges();
-        zone.simulateZoneExit();
-        // Note: should not have a detectChanges call here
-        // in order for the test to fail when it's supposed to.
-
-        expect(overlayContainerElement.querySelectorAll('mat-option')[0].classList)
-            .toContain('mat-active', 'Expected first option to be highlighted.');
-      }));
-
     it('should be able to configure preselecting the first option globally', fakeAsync(() => {
       overlayContainer.ngOnDestroy();
       fixture.destroy();