Fix text crossfade

When expanding a notification and changing the text displayed, fade-out
the going-away text earlier, and fade-in the new text later.

This avoids a state in between where some text is drawn on top of
other text.

Test: Create notification with long text, use drag to slowly expand
      notification. Check that text is never drawn on top of each other
Bug: 232852389
Change-Id: If0eb86aaf858ba7b2043bca56c4c70196709f078

packages/SystemUI/src/com/android/systemui/statusbar/notification/TransformState.java

@@ -16,6 +16,7 @@
 
 package com.android.systemui.statusbar.notification;
 
+import android.util.MathUtils;
 import android.util.Pools;
 import android.view.View;
 import android.view.animation.Interpolator;
@@ -98,7 +99,10 @@ public class TransformState {
         if (sameAs(otherState)) {
             ensureVisible();
         } else {
-            CrossFadeHelper.fadeIn(mTransformedView, transformationAmount, true /* remap */);
+            CrossFadeHelper.fadeIn(
+                    mTransformedView,
+                    MathUtils.constrainedMap(0, 1, 0.45f, 1, transformationAmount),
+                    false /* remap */);
         }
         transformViewFullyFrom(otherState, transformationAmount);
     }
@@ -294,7 +298,10 @@ public class TransformState {
             }
             return false;
         } else {
-            CrossFadeHelper.fadeOut(mTransformedView, transformationAmount);
+            CrossFadeHelper.fadeOut(
+                    mTransformedView,
+                    MathUtils.constrainedMap(0, 1, 0, 0.55f, transformationAmount),
+                    false /* remap */);
         }
         transformViewFullyTo(otherState, transformationAmount);
         return true;