message: test(common): fix double instantiation in NgSwitch test
  One of the tests was creating TestComponent instance _and_ using
  global state making this test not predictable. Fixing the test
  by making sure that TestComponent is instantiated only once.
  PR Close
diff: @@ -133,9 +133,7 @@ import {expect} from '@angular/platform-browser/testing/src/matchers';
  '</div>';
  TestBed.configureTestingModule({declarations: [TestDirective]});
  - TestBed.overrideComponent(TestComponent, {set: {template: template}})
  - .createComponent(TestComponent);
  - const fixture = TestBed.createComponent(TestComponent);
  + const fixture = createTestComponent(template);
  fixture.componentInstance.switchValue = 'a';
  fixture.detectChanges();
  