Add comment for locking down custom task animation.
Bug: 162066454
Test: N/A, comment change only
Change-Id: Ie014c70cf5253dc6107d2da10414278e36f9bd08
diff --git a/core/java/android/app/Activity.java b/core/java/android/app/Activity.java
index 530666b..e6b154b 100644
--- a/core/java/android/app/Activity.java
+++ b/core/java/android/app/Activity.java
@@ -6139,6 +6139,10 @@
* you to specify a custom animation even when starting an activity from
* outside the context of the current top activity.
*
+ * <p>Af of {@link android.os.Build.VERSION_CODES#S} application can only specify
+ * a transition animation when the transition happens within the same task. System
+ * default animation is used for cross-task transition animations.
+ *
* @param enterAnim A resource ID of the animation resource to use for
* the incoming activity. Use 0 for no animation.
* @param exitAnim A resource ID of the animation resource to use for