refactor(material/dialog): replace left-over module imports with standalone equivalents

Author: nikos-moysiadis

src/material/dialog/dialog-container.html

@@ -1,5 +1,5 @@
 <div class="mdc-dialog__container">
   <div class="mat-mdc-dialog-surface mdc-dialog__surface">
-    <ng-template cdkPortalOutlet></ng-template>
+    <ng-template cdkPortalOutlet />
   </div>
 </div>

src/material/dialog/dialog-container.ts

@@ -25,7 +25,7 @@ import {MatDialogConfig} from './dialog-config';
 import {ANIMATION_MODULE_TYPE} from '@angular/platform-browser/animations';
 import {CdkDialogContainer} from '@angular/cdk/dialog';
 import {coerceNumberProperty} from '@angular/cdk/coercion';
-import {ComponentPortal, PortalModule} from '@angular/cdk/portal';
+import {CdkPortalOutlet, ComponentPortal} from '@angular/cdk/portal';
 
 /** Event that captures the state of dialog container animations. */
 interface LegacyDialogAnimationEvent {
@@ -57,7 +57,7 @@ export const CLOSE_ANIMATION_DURATION = 75;
   // tslint:disable-next-line:validate-decorators
   changeDetection: ChangeDetectionStrategy.Default,
   standalone: true,
-  imports: [PortalModule],
+  imports: [CdkPortalOutlet],
   host: {
     'class': 'mat-mdc-dialog-container mdc-dialog',
     'tabindex': '-1',