build(aio): change examples to CLI (#19248)

PR Close #19248

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

@@ -1,7 +1,7 @@
 import { Component } from '@angular/core';
 
 @Component({
-  selector: 'my-app-ctor',
+  selector: 'app-ctor',
   template: `
     <h1>{{title}} [Ctor version]</h1>
     <h2>My favorite hero is: {{myHero}}</h2>

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

@@ -2,7 +2,7 @@
 import { Component } from '@angular/core';
 
 @Component({
-  selector: 'my-app',
+  selector: 'app-root',
   // #docregion template
   template: `
     <h1>{{title}}</h1>

aio/content/examples/displaying-data/src/app/app.component.2.ts

@@ -2,7 +2,7 @@
 import { Component } from '@angular/core';
 
 @Component({
-  selector: 'my-app',
+  selector: 'app-root',
   // #docregion template
   template: `
     <h1>{{title}}</h1>

aio/content/examples/displaying-data/src/app/app.component.3.ts

@@ -6,7 +6,7 @@ import { Hero } from './hero';
 // #enddocregion import
 
 @Component({
-  selector: 'my-app',
+  selector: 'app-root',
   // #docregion template
   template: `
     <h1>{{title}}</h1>

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

@@ -5,7 +5,7 @@ import { Component } from '@angular/core';
 import { Hero } from './hero';
 
 @Component({
-  selector: 'my-app',
+  selector: 'app-root',
   template: `
   <h1>{{title}}</h1>
   <h2>My favorite hero is: {{myHero.name}}</h2>