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

Relates to #9380

modules/@angular/compiler/test/html_ast_spec_utils.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 {HtmlAst, HtmlAstVisitor, HtmlAttrAst, HtmlCommentAst, HtmlElementAst, HtmlExpansionAst, HtmlExpansionCaseAst, HtmlTextAst, htmlVisitAll} from '@angular/compiler/src/html_ast';
 import {HtmlParseTreeResult} from '@angular/compiler/src/html_parser';
 import {ParseLocation} from '@angular/compiler/src/parse_util';