chore(Test): Replace simple use of DebugElement with @ViewChild.
chore(Test): Replace simple use of DebugElement with @ViewChild.

PiperOrigin-RevId: 183847244

angulardart/angular,matanlurey/angular,matanlurey/angular,angulardart/angular,chalin/angular2,kevmoo/angular,angulardart/angular,kevmoo/angular,chalin/angular2,kevmoo/angular,matanlurey/angular,chalin/angular2