chore: fix autocomplete demo in dev app (#17008)

Fixes the autocomplete demo not working correctly, because some testing changes weren't cleaned up in #15606.

Author: crisbeto

src/dev-app/autocomplete/autocomplete-demo.ts

@@ -6,7 +6,7 @@
  * found in the LICENSE file at https://angular.io/license
  */
 
-import {Component, ViewChild, ViewEncapsulation} from '@angular/core';
+import {Component, ViewChild} from '@angular/core';
 import {FormControl, NgModel} from '@angular/forms';
 import {Observable} from 'rxjs';
 import {map, startWith} from 'rxjs/operators';
@@ -26,8 +26,7 @@ export interface StateGroup {
   moduleId: module.id,
   selector: 'autocomplete-demo',
   templateUrl: 'autocomplete-demo.html',
-  styleUrls: ['autocomplete-demo.css'],
-  encapsulation: ViewEncapsulation.ShadowDom
+  styleUrls: ['autocomplete-demo.css']
 })
 export class AutocompleteDemo {
   stateCtrl: FormControl;