docs(back-button): update angular to standalone

Author: brandyscarney

static/usage/v7/back-button/basic/angular/example_component_ts.md

@@ -7,6 +7,7 @@ import { PageOneComponent } from './page-one.component';
 @Component({
   selector: 'app-example',
   templateUrl: 'example.component.html',
+  styleUrls: ['example.component.css'],
   imports: [IonNav],
 })
 export class ExampleComponent {

static/usage/v7/back-button/custom/angular/example_component_ts.md

@@ -7,6 +7,7 @@ import { PageOneComponent } from './page-one.component';
 @Component({
   selector: 'app-example',
   templateUrl: 'example.component.html',
+  styleUrls: ['example.component.css'],
   imports: [IonNav],
 })
 export class ExampleComponent {

static/usage/v8/back-button/basic/angular/example_component_ts.md

@@ -7,6 +7,7 @@ import { PageOneComponent } from './page-one.component';
 @Component({
   selector: 'app-example',
   templateUrl: 'example.component.html',
+  styleUrls: ['example.component.css'],
   imports: [IonNav],
 })
 export class ExampleComponent {

static/usage/v8/back-button/custom/angular/example_component_ts.md

@@ -7,6 +7,7 @@ import { PageOneComponent } from './page-one.component';
 @Component({
   selector: 'app-example',
   templateUrl: 'example.component.html',
+  styleUrls: ['example.component.css'],
   imports: [IonNav],
 })
 export class ExampleComponent {