message: docs(aio): remove "_" from private property name
  follow best practices from the documentation:
diff: @@ -24,7 +24,7 @@ export class AdBannerComponent implements AfterViewInit, OnDestroy {
  subscription: any;
  interval: any;
  - constructor(private _componentFactoryResolver: ComponentFactoryResolver) { }
  + constructor(private componentFactoryResolver: ComponentFactoryResolver) { }
  ngAfterViewInit() {
  this.loadComponent();
  @@ -39,7 +39,7 @@ export class AdBannerComponent implements AfterViewInit, OnDestroy {
  this.currentAddIndex = (this.currentAddIndex + 1) % this.ads.length;
  let adItem = this.ads[this.currentAddIndex];
  - let componentFactory = this._componentFactoryResolver.resolveComponentFactory(adItem.component);
  + let componentFactory = this.componentFactoryResolver.resolveComponentFactory(adItem.component);
  let viewContainerRef = this.adHost.viewContainerRef;
  viewContainerRef.clear();
  