chore(lint): Added license headers to most TypeScript files

Relates to #9380

modules/@angular/platform-browser/test/dom/events/event_manager_spec.ts

@@ -1,3 +1,11 @@
+/**
+ * @license
+ * Copyright Google Inc. All Rights Reserved.
+ *
+ * Use of this source code is governed by an MIT-style license that can be
+ * found in the LICENSE file at https://angular.io/license
+ */
+
 import {describe, ddescribe, it, iit, xit, xdescribe, expect, beforeEach,} from '@angular/core/testing/testing_internal';
 import {DomEventsPlugin} from '@angular/platform-browser/src/dom/events/dom_events';
 import {NgZone} from '@angular/core/src/zone/ng_zone';

modules/@angular/platform-browser/test/dom/events/key_events_spec.ts

@@ -1,3 +1,11 @@
+/**
+ * @license
+ * Copyright Google Inc. All Rights Reserved.
+ *
+ * Use of this source code is governed by an MIT-style license that can be
+ * found in the LICENSE file at https://angular.io/license
+ */
+
 import {describe, ddescribe, it, iit, xit, xdescribe, expect, beforeEach,} from '@angular/core/testing/testing_internal';
 import {KeyEventsPlugin} from '@angular/platform-browser/src/dom/events/key_events';