Reparent task back to the surface control during change transitions

Test: manual - expand a bubble and swipe up to collapse it
             - do this repeatedly and observe the animation doesn't
               flash the task at the top of the screen
Bug: 279074446
Change-Id: I81ece15a1fb21bfb9687540b96cb1baaafb74cb4

libs/WindowManager/Shell/src/com/android/wm/shell/taskview/TaskViewTaskController.java

@@ -82,6 +82,10 @@ public class TaskViewTaskController implements ShellTaskOrganizer.TaskListener {
         mGuard.open("release");
     }
 
+    SurfaceControl getSurfaceControl() {
+        return mSurfaceControl;
+    }
+
     /**
      * Sets the provided {@link TaskViewBase}, which is used to notify the client part about the
      * task related changes and getting the current bounds.

libs/WindowManager/Shell/src/com/android/wm/shell/taskview/TaskViewTransitions.java

@@ -336,6 +336,19 @@ public class TaskViewTransitions implements Transitions.TransitionHandler {
                 tv.prepareOpenAnimation(taskIsNew, startTransaction, finishTransaction,
                         chg.getTaskInfo(), chg.getLeash(), wct);
                 changesHandled++;
+            } else if (chg.getMode() == TRANSIT_CHANGE) {
+                TaskViewTaskController tv = findTaskView(chg.getTaskInfo());
+                if (tv == null) {
+                    if (pending != null) {
+                        Slog.w(TAG, "Found a non-TaskView task in a TaskView Transition. This "
+                                + "shouldn't happen, so there may be a visual artifact: "
+                                + chg.getTaskInfo().taskId);
+                    }
+                    continue;
+                }
+                startTransaction.reparent(chg.getLeash(), tv.getSurfaceControl());
+                finishTransaction.reparent(chg.getLeash(), tv.getSurfaceControl());
+                changesHandled++;
             }
         }
         if (stillNeedsMatchingLaunch) {