Fixed weirdness about last icon in shelf

The last icon in shelf could jump around and behave
Erratically because of an optimization around it's
transformation.
If the maxShelfEnd changed non-continuously, for example
With an expansion, the icon would jump-cut.

Test: add a few notifications, while no shelf available, expand notification
Before the last one, observe no jump-cut

Change-Id: I4b05f340cb1715f7bf80f5e96582a56a6f62ce1b

packages/SystemUI/src/com/android/systemui/statusbar/NotificationShelf.java

@@ -388,12 +388,13 @@ public class NotificationShelf extends ActivatableNotificationView {
 
         View rowIcon = row.getNotificationIcon();
         float notificationIconPosition = row.getTranslationY() + row.getContentTranslation();
-        if (usingLinearInterpolation) {
+        boolean stayingInShelf = row.isInShelf() && !row.isTransformingIntoShelf();
+        if (usingLinearInterpolation && !stayingInShelf) {
             // If we interpolate from the notification position, this might lead to a slightly
             // odd interpolation, since the notification position changes as well. Let's interpolate
             // from a fixed distance. We can only do this if we don't animate and the icon is
             // always in the interpolated positon.
-            notificationIconPosition = mMaxShelfEnd - getIntrinsicHeight() - iconTransformDistance;
+            notificationIconPosition = getTranslationY() - iconTransformDistance;
         }
         float notificationIconSize = 0.0f;
         int iconTopPadding;
@@ -426,7 +427,7 @@ public class NotificationShelf extends ActivatableNotificationView {
             iconState.hidden = transitionAmount == 0.0f;
             iconState.alpha = alpha;
             iconState.yTranslation = iconYTranslation;
-            if (row.isInShelf() && !row.isTransformingIntoShelf()) {
+            if (stayingInShelf) {
                 iconState.iconAppearAmount = 1.0f;
                 iconState.alpha = 1.0f;
                 iconState.scaleX = 1.0f;