DragHandler catches events when tumbler is dragged

TouchEvents for dragging are captured by drag handlers beneath dialog.

In the attached project, we have a small example of a rectangle with a drag handler, and a dialog, which is explicitly after the dragged item in stacking order. Events from the dialog still trigger the draghandler beneath and make the tumbler unusable with dialogs.

The same actually happens with the ListView of ComboBoxes. When the View is dragged, the drag handler below the dialog also receives the drag.

In our case, the dialog is created dynamically and we cannot explicitly connect the dragHandler enabled state with dialog.opened.

This seems to be specific to drag handlers underneath the dialog. AbstractButtons for example do not receive events when a dialog is opened on top of them.