refactor(docs-infra): fix `strictTemplates` failures in `accessibility` docs example (#39248)

fix `strictTemplates` failures in `accessibility` docs example

PR Close #39248

aio/content/examples/accessibility/e2e/src/app.e2e-spec.ts

@@ -12,7 +12,7 @@ describe('Accessibility example e2e tests', () => {
 
   it('should take a number and change progressbar width', () => {
     element(by.css('input')).sendKeys('16');
-    expect(element(by.css('input')).getAttribute('value')).toEqual('016');
+    expect(element(by.css('input')).getAttribute('value')).toEqual('16');
     expect(element(by.css('app-example-progressbar div')).getCssValue('width')).toBe('48px');
   });
 

aio/content/examples/accessibility/src/app/app.component.html

@@ -3,7 +3,7 @@
 <label>
   Enter an example progress value
   <input type="number" min="0" max="100"
-      [value]="progress" (input)="progress = $event.target.value">
+      [value]="progress" (input)="setProgress($event)">
 </label>
 
 <!-- The user of the progressbar sets an aria-label to communicate what the progress means. -->

aio/content/examples/accessibility/src/app/app.component.ts

@@ -7,4 +7,8 @@ import { Component } from '@angular/core';
 })
 export class AppComponent  {
   progress = 0;
+
+  setProgress($event: Event) {
+    this.progress = +($event.target as HTMLInputElement).value;
+  }
 }