fix(@angular/pwa): Install new dependencies

fixes #10332

Author: Brocco

packages/angular/pwa/pwa/index.ts

@@ -19,6 +19,7 @@ import {
   template,
   url,
 } from '@angular-devkit/schematics';
+import { NodePackageInstallTask } from '@angular-devkit/schematics/tasks';
 import { getWorkspace } from '../utility/config';
 import { Schema as PwaOptions } from './schema';
 
@@ -45,6 +46,8 @@ export default function (options: PwaOptions): Rule {
       move(assetPath),
     ]);
 
+    context.addTask(new NodePackageInstallTask());
+
     return chain([
       addServiceWorker(options),
       branchAndMerge(chain([