DOCX drawingML shape import: fix sw text frame transparence
DOCX drawingML shape import: fix sw text frame transparence

Mirror what the VML import's ShapeBase::convertShapeProperties() already
does, fixes CppunitTest_sw_ooxmlexport's testFdo66688 when wps import is
enabled by default.

Change-Id: Iabed3a5fa1353aefe3055232ad0b7770067a7a58

JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core