build(docs-infra): update project structure to cli@9 1/12 (app.po.ts) (angular#36015)

Update `app.po.ts`.

PR Close angular#36015

Author: gkalpak

aio/tools/examples/shared/boilerplate/cli/e2e/src/app.po.ts

@@ -1,11 +1,11 @@
 import { browser, by, element } from 'protractor';
 
 export class AppPage {
-  navigateTo() {
-    return browser.get(browser.baseUrl) as Promise<any>;
+  navigateTo(): Promise<unknown> {
+    return browser.get(browser.baseUrl) as Promise<unknown>;
   }
 
-  getTitleText() {
+  getTitleText(): Promise<string> {
     return element(by.css('app-root h1')).getText() as Promise<string>;
   }
 }