fixup! fix(material-experimental/mdc-slider): code review changes

Author: wagnermaciel

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

@@ -6,7 +6,11 @@
  * found in the LICENSE file at https://angular.io/license
  */
 
-import {dispatchMouseEvent, dispatchPointerEvent, dispatchTouchEvent} from '@angular/cdk/testing/private';
+import {
+  dispatchMouseEvent,
+  dispatchPointerEvent,
+  dispatchTouchEvent,
+} from '@angular/cdk/testing/private';
 import {Component, DebugElement, Type} from '@angular/core';
 import {ComponentFixture, fakeAsync, TestBed, tick, waitForAsync} from '@angular/core/testing';
 import {By} from '@angular/platform-browser';
@@ -335,22 +339,22 @@ function dispatchPointerOrTouchEvent(node: Node, type: PointerEventType, x?: num
 }
 
 /** The pointer event types used by the MDC Slider. */
-enum PointerEventType {
+const enum PointerEventType {
   POINTER_DOWN = 'pointerdown',
   POINTER_UP = 'pointerup',
   POINTER_MOVE = 'pointermove',
 }
 
 /** The touch event types used by the MDC Slider. */
-enum TouchEventType {
+const enum TouchEventType {
   TOUCH_START = 'touchstart',
   TOUCH_END = 'touchend',
   TOUCH_MOVE = 'touchmove',
 }
 
 /** Returns the touch event equivalent of the given pointer event. */
 function pointerEventTypeToTouchEventType(pointerEventType: PointerEventType) {
-  switch(pointerEventType) {
+  switch (pointerEventType) {
     case PointerEventType.POINTER_DOWN:
       return TouchEventType.TOUCH_START;
     case PointerEventType.POINTER_UP: