refactor: fix undecorated classes with angular features in repo (#36921)

A few instances of undecorated classes with Angular features
have been discovered in the framework repo. This commit fixes
those.

PR Close #36921

aio/content/examples/lifecycle-hooks/src/app/peek-a-boo.component.ts

@@ -3,6 +3,7 @@ import {
   AfterContentInit,
   AfterViewChecked,
   AfterViewInit,
+  Directive,
   DoCheck,
   OnChanges,
   OnDestroy,
@@ -15,7 +16,8 @@ import { LoggerService }    from './logger.service';
 let nextId = 1;
 
 // #docregion ngOnInit
-export class PeekABoo implements OnInit {
+@Directive()
+export class PeekABooDirective implements OnInit {
   constructor(private logger: LoggerService) { }
 
   // implement OnInit's `ngOnInit` method
@@ -34,7 +36,7 @@ export class PeekABoo implements OnInit {
 })
 // Don't HAVE to mention the Lifecycle Hook interfaces
 // unless we want typing and tool support.
-export class PeekABooComponent extends PeekABoo implements
+export class PeekABooComponent extends PeekABooDirective implements
              OnChanges, OnInit, DoCheck,
              AfterContentInit, AfterContentChecked,
              AfterViewInit, AfterViewChecked,

packages/forms/src/directives/abstract_form_group_directive.ts

@@ -6,7 +6,7 @@
  * found in the LICENSE file at https://angular.io/license
  */
 
-import {OnDestroy, OnInit} from '@angular/core';
+import {Directive, OnDestroy, OnInit} from '@angular/core';
 
 import {FormGroup} from '../model';
 
@@ -23,6 +23,7 @@ import {AsyncValidatorFn, ValidatorFn} from './validators';
  *
  * @publicApi
  */
+@Directive()
 export class AbstractFormGroupDirective extends ControlContainer implements OnInit, OnDestroy {
   /**
    * @description

packages/router/src/router.ts

@@ -7,8 +7,8 @@
  */
 
 import {Location} from '@angular/common';
-import {Compiler, Injector, isDevMode, NgModuleFactoryLoader, NgModuleRef, NgZone, Type, ɵConsole as Console} from '@angular/core';
+import {Compiler, Injectable, Injector, isDevMode, NgModuleFactoryLoader, NgModuleRef, NgZone, Type, ɵConsole as Console} from '@angular/core';
-import {BehaviorSubject, defer, EMPTY, Observable, of, Subject, Subscription} from 'rxjs';
+import {BehaviorSubject, EMPTY, Observable, of, Subject, Subscription} from 'rxjs';
 import {catchError, filter, finalize, map, switchMap, tap} from 'rxjs/operators';
 
 import {QueryParamsHandling, Route, Routes, standardizeConfig, validateConfig} from './config';
@@ -288,6 +288,7 @@ function defaultRouterHook(snapshot: RouterStateSnapshot, runExtras: {
  *
  * @publicApi
  */
+@Injectable()
 export class Router {
   private currentUrlTree: UrlTree;
   private rawUrlTree: UrlTree;

packages/router/src/router_scroller.ts

@@ -7,12 +7,13 @@
  */
 
 import {ViewportScroller} from '@angular/common';
-import {OnDestroy} from '@angular/core';
+import {Injectable, OnDestroy} from '@angular/core';
 import {Unsubscribable} from 'rxjs';
 
 import {NavigationEnd, NavigationStart, Scroll} from './events';
 import {Router} from './router';
 
+@Injectable()
 export class RouterScroller implements OnDestroy {
   // TODO(issue/24571): remove '!'.
   private routerEventsSubscription!: Unsubscribable;

packages/upgrade/src/dynamic/src/upgrade_ng1_adapter.ts

@@ -135,6 +135,7 @@ export class UpgradeNg1ComponentAdapterBuilder {
   }
 }
 
+@Directive()
 class UpgradeNg1ComponentAdapter implements OnInit, OnChanges, DoCheck {
   private controllerInstance: IControllerInstance|null = null;
   destinationObj: IBindingDestination|null = null;

packages/upgrade/static/src/upgrade_component.ts

@@ -6,9 +6,9 @@
  * found in the LICENSE file at https://angular.io/license
  */
 
-import {DoCheck, ElementRef, EventEmitter, Injector, OnChanges, OnDestroy, OnInit, SimpleChanges, ɵlooseIdentical as looseIdentical} from '@angular/core';
+import {Directive, DoCheck, ElementRef, EventEmitter, Injector, OnChanges, OnDestroy, OnInit, SimpleChanges, ɵlooseIdentical as looseIdentical} from '@angular/core';
 
-import {IAttributes, IAugmentedJQuery, IDirective, IDirectivePrePost, IInjectorService, ILinkFn, IScope, ITranscludeFunction} from '../../src/common/src/angular1';
+import {IAttributes, IAugmentedJQuery, IDirective, IInjectorService, ILinkFn, IScope, ITranscludeFunction} from '../../src/common/src/angular1';
 import {$SCOPE} from '../../src/common/src/constants';
 import {IBindingDestination, IControllerInstance, UpgradeHelper} from '../../src/common/src/upgrade_helper';
 import {isFunction} from '../../src/common/src/util';
@@ -66,6 +66,7 @@ class Bindings {
  *
  * @publicApi
  */
+@Directive()
 export class UpgradeComponent implements OnInit, OnChanges, DoCheck, OnDestroy {
   private helper: UpgradeHelper;