docs: rename component for constructor example (#30845)

PR Close #30845

aio/content/examples/displaying-data/src/app/app-ctor.component.1.ts

@@ -1,14 +1,14 @@
 import { Component } from '@angular/core';
 
 @Component({
-  selector: 'app-ctor',
+  selector: 'app-root',
   template: `
     <h1>{{title}} [Ctor version]</h1>
     <h2>My favorite hero is: {{myHero}}</h2>
     `
 })
 // #docregion class
-export class AppCtorComponent {
+export class AppComponent {
   title: string;
   myHero: string;