fix(cdk/testing): fake touch event does not touch identifier

The fake `TouchEvent` being created by test harnesses for the
TestBed harness environment currently set an id for a `Touch`
of the fake event. The `Touch` currently incorrectly sets the
unique touch id to a field named `id`, while it should be `identifier`.

Author: devversion

src/cdk/testing/testbed/fake-events/event-objects.ts

@@ -27,6 +27,9 @@ export function createMouseEvent(
   const event = new MouseEvent(type, {
     bubbles: true,
     cancelable: true,
+    view: window,
+    detail: 0,
+    relatedTarget: null,
     screenX,
     screenY,
     clientX,
@@ -77,7 +80,7 @@ export function createTouchEvent(type: string, pageX = 0, pageY = 0, clientX = 0
   // We cannot use the `TouchEvent` or `Touch` because Firefox and Safari lack support.
   // TODO: Switch to the constructor API when it is available for Firefox and Safari.
   const event = document.createEvent('UIEvent');
-  const touchDetails = {pageX, pageY, clientX, clientY, id: uniqueIds++};
+  const touchDetails = {pageX, pageY, clientX, clientY, identifier: uniqueIds++};
 
   // TS3.6 removes the initUIEvent method and suggests porting to "new UIEvent()".
   (event as any).initUIEvent(type, true, true, window, 0);