[NUI] Change the call to GetRootLayer() so that the layer index can be updated.

If the root layer index is not updated and another layer is added first, a problem occurs in calculating the layer index.
Something like LowerBelow may not work.

diff --git a/src/Tizen.NUI/src/public/Window/Window.cs b/src/Tizen.NUI/src/public/Window/Window.cs
index dc80b3f..f844968 100755 (executable)
--- a/src/Tizen.NUI/src/public/Window/Window.cs
+++ b/src/Tizen.NUI/src/public/Window/Window.cs
@@ -1383,7 +1383,7 @@ namespace Tizen.NUI
 
             if (isBorderWindow)
             {
-                Interop.Actor.Add(GetBorderWindowRootLayer().SwigCPtr, layer.SwigCPtr);
+                Interop.Actor.Add(GetRootLayer().SwigCPtr, layer.SwigCPtr);
                 if (NDalicPINVOKE.SWIGPendingException.Pending) { throw NDalicPINVOKE.SWIGPendingException.Retrieve(); }
             }
             else