Avoid conflict surface reset on auto-enter-pip

FullscreenUnfoldController#resetSurface happens in between
RecentsAnimationController cleanup and PipTaskOrganizer#onTaskAppeared
may cause flicker at the end of auto-enter-pip transition.

Fix it by intentionally ignore resetSurface if the task's pinned.

Bug: 203724707
Bug: 204284060
Test: repeatedly swipe to enter PiP from YT on foldables
Change-Id: Ie074e8a506d2526fc081ff4d089a2acb00549286
diff --git a/libs/WindowManager/Shell/src/com/android/wm/shell/fullscreen/FullscreenUnfoldController.java b/libs/WindowManager/Shell/src/com/android/wm/shell/fullscreen/FullscreenUnfoldController.java
index fc1b704..aa3868c 100644
--- a/libs/WindowManager/Shell/src/com/android/wm/shell/fullscreen/FullscreenUnfoldController.java
+++ b/libs/WindowManager/Shell/src/com/android/wm/shell/fullscreen/FullscreenUnfoldController.java
@@ -16,6 +16,7 @@
 
 package com.android.wm.shell.fullscreen;
 
+import static android.app.WindowConfiguration.WINDOWING_MODE_PINNED;
 import static android.util.MathUtils.lerp;
 import static android.view.Display.DEFAULT_DISPLAY;
 
@@ -163,7 +164,10 @@
     public void onTaskVanished(ActivityManager.RunningTaskInfo taskInfo) {
         AnimationContext animationContext = mAnimationContextByTaskId.get(taskInfo.taskId);
         if (animationContext != null) {
-            resetSurface(animationContext);
+            // PiP task has its own cleanup path, ignore surface reset to avoid conflict.
+            if (taskInfo.getWindowingMode() != WINDOWING_MODE_PINNED) {
+                resetSurface(animationContext);
+            }
             mAnimationContextByTaskId.remove(taskInfo.taskId);
         }