fixup! test(material-experimental/mdc-slider): add tests for sliders with se… (#22214)

Author: wagnermaciel

src/material-experimental/mdc-slider/slider.spec.ts

@@ -9,7 +9,7 @@
 import {LEFT_ARROW, RIGHT_ARROW} from '@angular/cdk/keycodes';
 import {Platform} from '@angular/cdk/platform';
 import {
-  dispatchEvent,
+  dispatchFakeEvent,
   dispatchMouseEvent,
   dispatchPointerEvent,
   dispatchTouchEvent,
@@ -807,7 +807,7 @@ function changeValueUsingArrowKeys(slider: MatSlider, arrow: number, thumbPositi
     ? input.value + slider.step
     : input.value - slider.step;
   input._hostElement.value = value.toString();
-  dispatchEvent(input._hostElement, new Event('change'));
+  dispatchFakeEvent(input._hostElement, 'change');
 }
 
 /** Dispatch a pointerdown or pointerup event if supported, otherwise dispatch the touch event. */