fix(animations): make sure the easing value is passed into the web-animations player

Closes #9517
Closes #9523

modules/@angular/platform-browser/src/dom/web_animations_driver.ts

@@ -50,6 +50,7 @@ export class WebAnimationsDriver implements AnimationDriver {
     var playerOptions = {
       'duration': duration,
       'delay': delay,
+      'easing': easing,
       'fill': 'both'  // we use `both` because it allows for styling at 0% to work with `delay`
     };