Don't do icon animations if we are scrolling fast

We are now not doing any icon animations anymore
in case we are scrolling fast.

Change-Id: I878d20a8e6114dc58c3908d18cc5ba20e59972cf
Test: add notifications, scroll fast
Bug: 32437839
diff --git a/packages/SystemUI/src/com/android/systemui/statusbar/stack/AmbientState.java b/packages/SystemUI/src/com/android/systemui/statusbar/stack/AmbientState.java
index 26f74ea..f468b5c 100644
--- a/packages/SystemUI/src/com/android/systemui/statusbar/stack/AmbientState.java
+++ b/packages/SystemUI/src/com/android/systemui/statusbar/stack/AmbientState.java
@@ -52,6 +52,7 @@
     private int mBaseZHeight;
     private int mMaxLayoutHeight;
     private ActivatableNotificationView mLastVisibleBackgroundChild;
+    private float mCurrentScrollVelocity;
 
     public AmbientState(Context context) {
         reload(context);
@@ -241,4 +242,12 @@
     public ActivatableNotificationView getLastVisibleBackgroundChild() {
         return mLastVisibleBackgroundChild;
     }
+
+    public void setCurrentScrollVelocity(float currentScrollVelocity) {
+        mCurrentScrollVelocity = currentScrollVelocity;
+    }
+
+    public float getCurrentScrollVelocity() {
+        return mCurrentScrollVelocity;
+    }
 }