sd/pptx export: allow exporting effect preset id.

Change-Id: I2a0149e7f47fe3d5abeea61c93d0a55782af3e6d
Reviewed-on: https://gerrit.libreoffice.org/59891
Tested-by: Jenkins
Reviewed-by: Mark Hung <marklh9@gmail.com>

sd/source/filter/eppt/pptx-animations.cxx

@@ -943,6 +943,7 @@ void PPTXAnimationExport::WriteAnimationNodeCommonPropsStart()
     if (rPresetId.getLength() > 0)
     {
         nPresetId = AnimationExporter::GetPresetID(rPresetId, nPresetClass, bPresetId);
+        bPresetId = true;
     }
 
     sal_uInt32 nPresetSubType = 0;