Apply detached task transactions on animation cleanup

If the task is detached while being animated by recents, the animation
leash may not be cleaned up properly. If the leash draws a shadow,
this would result in a translucent layer on screen that cannot be
dismissed.

The leash was not being cleaned up because when the task is detached,
it will use its own transaction instead of its DC transaction and its
transaction is not reachable.

Bug: 172932178
Test: while dragging app to recents, adb shell am force-stop <package>, drag back to home

Change-Id: Id84319c8ab224c11c6f9ab623b949bba61c761fd

services/core/java/com/android/server/wm/RecentsAnimationController.java

@@ -763,7 +763,7 @@ public class RecentsAnimationController implements DeathRecipient {
                 taskAdapter.mTask.dontAnimateDimExit();
             }
             removeAnimation(taskAdapter);
-            taskAdapter.maybeApplyFinishBounds();
+            taskAdapter.onCleanup();
         }
 
         for (int i = mPendingWallpaperAnimations.size() - 1; i >= 0; i--) {
@@ -987,14 +987,19 @@ public class RecentsAnimationController implements DeathRecipient {
             return mTarget;
         }
 
-        void maybeApplyFinishBounds() {
+        void onCleanup() {
             if (!mFinishBounds.isEmpty()) {
+                // Apply any pending bounds changes
                 final SurfaceControl taskSurface = mTask.getSurfaceControl();
                 mTask.getPendingTransaction()
                         .setPosition(taskSurface, mFinishBounds.left, mFinishBounds.top)
                         .setWindowCrop(taskSurface, mFinishBounds.width(), mFinishBounds.height())
                         .apply();
                 mFinishBounds.setEmpty();
+            } else {
+                // Apply the task's pending transaction in case it is detached and its transaction
+                // is not reachable.
+                mTask.getPendingTransaction().apply();
             }
         }