TextEditor - Update the decoration box's size.
TextEditor - Update the decoration box's size.

* Sets the decoration bounding box the size of the text-editor control.
  This prevents the popup to be positioned on top of the virtual keyboard
  or the top bar.

Change-Id: I317d2289e740725b8e39746feeccad5ff664827e
Signed-off-by: Victor Cebollada <bd4ca07245b7f4eb2d3ace02513dff6e050d7f4b@samsung.com>

dalihub/dali-demo,dalihub/dali-demo,dalihub/dali-demo,dalihub/dali-demo