Bug fix for GraphicElement masks
SDK-19224 Incorrect drawing after adding a mask to an existing GraphicElement
The bug occurs when the mask gets added after the GraphicElement has already drawn and gone through a layout pass. Adding an unparented mask requires the GraphicElement to create a drawnDisplayObject and attach it and the mask to the displayObject. When the mask is added later, we need to clear the original displayObject's graphics object.
QE Notes: Check dynamically adding and removing masks from GraphicElement
Doc Notes: None