fix(core): export animation classes required for Renderer impl

Closes angular#14001

modules/@angular/core/src/animation/animation_keyframe.ts

@@ -8,6 +8,9 @@
 
 import {AnimationStyles} from './animation_styles';
 
+/**
+ * @experimental
+ */
 export class AnimationKeyframe {
   constructor(public offset: number, public styles: AnimationStyles) {}
 }

modules/@angular/core/src/animation/animation_styles.ts

@@ -6,6 +6,9 @@
  * found in the LICENSE file at https://angular.io/license
  */
 
+/**
+ * @experimental
+ */
 export class AnimationStyles {
   constructor(public styles: {[key: string]: string | number}[]) {}
 }

modules/@angular/core/src/core.ts

@@ -34,5 +34,7 @@ export {ErrorHandler} from './error_handler';
 export * from './core_private_export';
 export * from './animation/metadata';
 export {AnimationTransitionEvent} from './animation/animation_transition_event';
-export {AnimationPlayer} from './animation/animation_player';
+export {AnimationPlayer, NoOpAnimationPlayer} from './animation/animation_player';
+export {AnimationStyles} from './animation/animation_styles';
+export {AnimationKeyframe} from './animation/animation_keyframe';
 export {Sanitizer, SecurityContext} from './security';

tools/public_api_guard/core/index.d.ts

@@ -44,6 +44,11 @@ export declare class AnimationGroupMetadata extends AnimationWithStepsMetadata {
     constructor(_steps: AnimationMetadata[]);
 }
 
+/** @experimental */
+export class AnimationKeyframe {
+  constructor(offset: number, styles: AnimationStyles);
+}
+
 /** @experimental */
 export declare class AnimationKeyframesSequenceMetadata extends AnimationMetadata {
     steps: AnimationStyleMetadata[];
@@ -95,6 +100,11 @@ export declare class AnimationStateTransitionMetadata extends AnimationStateMeta
     constructor(stateChangeExpr: string | ((fromState: string, toState: string) => boolean), steps: AnimationMetadata);
 }
 
+/** @experimental */
+export class AnimationStyles {
+  constructor(styles: {[key: string]: string | number}[]);
+}
+
 /** @experimental */
 export declare class AnimationStyleMetadata extends AnimationMetadata {
     offset: number;