fdo76201:File Corruption - Issue related with prstGeom for Hexagon shape.

  There are two issues that are handled in this fix.
  1)File created in MSO2K10 on RT gets corrupted.The root cause is found in CustomShapeProperties::pushToPropSet
  2)File created in MSO2K7 on RT gets corrupted.There is an issue in shape import <a:gd> values for any shape (ex. circular arrow, hexagon etc).LO cannot import right <a:gd> values for any shape  which is created in MSO-2007.Due to missing values of <a:gd> tag, after roundtrip the file gets corrupted.To avoid corruption a check introduced:-
    if(aAdjustments.size() == nLength)
    after http://opengrok.libreoffice.org/xref/core/oox/source/export/drawingml.cxx#1784
    that will verify the number of <a:gd> tags associated with the shape during import and the number of <a:gd> tags during export.If there is a mismatch <a:gd> willnot be written.Changes made in DrawingML::WritePresetShape.
I have written 2 test cases for the same.

Conflicts:
	sw/qa/extras/ooxmlexport/ooxmlexport.cxx

Reviewed on:
	https://gerrit.libreoffice.org/8657

Change-Id: Ibb1e2dc1c098b7399c06d7b4f59fac4e80887062