Only allow roots tasks to be organized

Non-root tasks are relative to their parents so no need to have them
return true to the isOrganized() method.
We can also:
- Reset the windowing mode for a task we are moving to split screen
before we reparent to the split task.
- Remove code in sys-ui that was added to compensate for the
method previous returning true.

Bug: 152619437
Test: They pass
Change-Id: I7a0381f535f2d0b245773ecb1fbb4fdb524954f9

packages/SystemUI/src/com/android/systemui/stackdivider/DividerView.java

@@ -1085,14 +1085,6 @@ public class DividerView extends FrameLayout implements OnTouchListener,
         crop.offsetTo(-(otherTaskRect.left - otherRect.left),
                 -(otherTaskRect.top - otherRect.top));
         t.setWindowCrop(mTiles.mSecondarySurface, crop);
-        // Reposition home and recents surfaces or they would be positioned relatively to its
-        // parent (split-screen secondary task) position.
-        for (int i = mTiles.mHomeAndRecentsSurfaces.size() - 1; i >= 0; --i) {
-            t.setPosition(mTiles.mHomeAndRecentsSurfaces.get(i),
-                    mTiles.mHomeBounds.left - otherTaskRect.left,
-                    mTiles.mHomeBounds.top - otherTaskRect.top);
-            t.setWindowCrop(mTiles.mHomeAndRecentsSurfaces.get(i), null);
-        }
         final SurfaceControl dividerCtrl = getWindowSurfaceControl();
         if (dividerCtrl != null) {
             if (isHorizontalDivision()) {

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

@@ -2802,6 +2802,9 @@ public class ActivityTaskManagerService extends IActivityTaskManager.Stub {
                     false /* includingParents */);
         }
         WindowContainerTransaction wct = new WindowContainerTransaction();
+        // Clear out current windowing mode before reparenting to split taks.
+        wct.setWindowingMode(
+                task.getStack().mRemoteToken.toWindowContainerToken(), WINDOWING_MODE_UNDEFINED);
         wct.reparent(task.getStack().mRemoteToken.toWindowContainerToken(),
                 primarySplitTask.mRemoteToken.toWindowContainerToken(), toTop);
         mWindowOrganizerController.applyTransaction(wct);

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

@@ -4068,21 +4068,7 @@ class Task extends WindowContainer<WindowContainer> {
 
     @Override
     boolean isOrganized() {
-        final Task rootTask = getRootTask();
+        return mTaskOrganizer != null;
-        if (rootTask.mTaskOrganizer == null) {
-            // You are obviously not organized...
-            return false;
-        }
-        if (rootTask == this) {
-            // Root tasks can be organized.
-            return true;
-        }
-        if (rootTask.mCreatedByOrganizer && getParent() == rootTask) {
-            // Direct children of tasks added by the organizer can the organized.
-            return true;
-        }
-
-        return false;
     }
 
     @Override
@@ -4137,6 +4123,7 @@ class Task extends WindowContainer<WindowContainer> {
         }
    }
 
+    @VisibleForTesting
     boolean setTaskOrganizer(ITaskOrganizer organizer) {
         if (mTaskOrganizer == organizer) {
             return false;