fix(aio): fix up typing errors in tests

The new version of Jasmine types identified issues with our unit tests.

aio/src/app/embedded/code/code-example.component.spec.ts

@@ -87,7 +87,7 @@ describe('CodeExampleComponent', () => {
 class TestCodeComponent {
   @Input() code = '';
   @Input() language: string;
-  @Input() linenums: boolean | number;
+  @Input() linenums: string;
   @Input() path: string;
   @Input() region: string;
   @Input() hideCopy: boolean;