fix(@schematics/angular): allow ServiceWorker to work with baseHref

Fixes #8515

Author: gkalpak

packages/schematics/angular/service-worker/index.ts

@@ -131,7 +131,7 @@ function updateAppModule(options: ServiceWorkerOptions): Rule {
 
     // register SW in app module
     const importText =
-      `ServiceWorkerModule.register('/ngsw-worker.js', { enabled: environment.production })`;
+      `ServiceWorkerModule.register('ngsw-worker.js', { enabled: environment.production })`;
     moduleSource = getTsSourceFile(host, modulePath);
     const metadataChanges = addSymbolToNgModuleMetadata(
       moduleSource, modulePath, 'imports', importText);

packages/schematics/angular/service-worker/index_spec.ts

@@ -87,8 +87,8 @@ describe('Service Worker Schematic', () => {
     const tree = schematicRunner.runSchematic('service-worker', defaultOptions, appTree);
     const pkgText = tree.readContent('/projects/bar/src/app/app.module.ts');
     // tslint:disable-next-line:max-line-length
-    const regex = /ServiceWorkerModule\.register\('\/ngsw-worker.js\', { enabled: environment.production }\)/;
-    expect(pkgText).toMatch(regex);
+    const expectedText = 'ServiceWorkerModule.register(\'ngsw-worker.js\', { enabled: environment.production })';
+    expect(pkgText).toContain(expectedText);
   });
 
   it('should put the ngsw-config.json file in the project root', () => {