Fix flickering when cancel cross activity animation.

Cross activity animation use different spring animations to control
different object/status, so the finish stage of each animations are
arrived separatly. For the cancel animation case, force update the
closing target to final stage before release all animation leashes.

Bug: 230798396
Test: manual enter/cancel animation and verify no flicker.
Change-Id: I82d99ce4bc922cf7ecb7013ef532e8b18c47c35a

libs/WindowManager/Shell/src/com/android/wm/shell/back/CrossActivityAnimation.java

@@ -371,7 +371,15 @@ class CrossActivityAnimation {
 
         @Override
         public void onBackCancelled() {
-            mProgressAnimator.onBackCancelled(CrossActivityAnimation.this::finishAnimation);
+            mProgressAnimator.onBackCancelled(() -> {
+                // mProgressAnimator can reach finish stage earlier than mLeavingProgressSpring,
+                // and if we release all animation leash first, the leavingProgressSpring won't
+                // able to update the animation anymore, which cause flicker.
+                // Here should force update the closing animation target to the final stage before
+                // release it.
+                setLeavingProgress(0);
+                finishAnimation();
+            });
         }
 
         @Override