Update animations for TM-QPR: Overview > OverviewSplitSelect transition

This change updates the Overview > OverviewSplitSelect animation to the latest spec. This is a re-upload of a previous change, ag/19464657, but no longer will cause the b/241165022 issue.

Includes:
- New timings
- Task thumbnails slide in with an "overshoot" animation
- Icons fade out and fade in appropriately
- SplitInstructionsView has a new compound "unfold" animation

Bug: 236760307
Test: Manual on tablet. Made sure the b/241165022 issue is fixed.
Change-Id: Ia22f6b6d7b9474b782e693fae2320a34a2985b18

quickstep/src/com/android/quickstep/views/TaskView.java

@@ -323,19 +323,6 @@ public class TaskView extends FrameLayout implements Reusable {
                 }
             };
 
-    public static final FloatProperty<TaskView> ICON_ALPHA =
-            new FloatProperty<TaskView>("iconAlpha") {
-                @Override
-                public void setValue(TaskView taskView, float v) {
-                    taskView.mIconView.setAlpha(v);
-                }
-
-                @Override
-                public Float get(TaskView taskView) {
-                    return taskView.mIconView.getAlpha();
-                }
-            };
-
     @Nullable
     protected Task mTask;
     protected TaskThumbnailView mSnapshotView;