Improved the animation logic of the stack scroller.

Newly introduced appear and disappear animations when in the shade.
Also introduced individual child delays such that notifications
appear in a slightly more appealing quantum way.
Also fixed a racecondition, such that added notifications already
have their final visibility state when they are added to the scroller.

Bug: 14081264
Change-Id: I18f5c57c2206f8e05996253981f540e97521e102
diff --git a/packages/SystemUI/src/com/android/systemui/statusbar/phone/NotificationPanelView.java b/packages/SystemUI/src/com/android/systemui/statusbar/phone/NotificationPanelView.java
index fe7546d..142241c 100644
--- a/packages/SystemUI/src/com/android/systemui/statusbar/phone/NotificationPanelView.java
+++ b/packages/SystemUI/src/com/android/systemui/statusbar/phone/NotificationPanelView.java
@@ -214,7 +214,7 @@
                         mClockAnimationTarget = -1;
                     }
                 });
-                StackStateAnimator.startInstantly(mClockAnimator);
+                mClockAnimator.start();
                 return true;
             }
         });