schema,sd: enable ODF validation in sd tests

There are actually 2 bugs here that affect the export, and just 1 new
attribute.

Change-Id: Id2d9eeeb62c97011712a376a844dec7c8a744116
Reviewed-on: https://gerrit.libreoffice.org/56606
Tested-by: Jenkins
Reviewed-by: Thorsten Behrens <Thorsten.Behrens@CIB.de>

sd/qa/unit/sdmodeltestbase.hxx

@@ -213,7 +213,7 @@ protected:
         save(pShell, pFormat, *pTempFile);
         if (nExportType == ODP || nExportType == ODG)
         {
-            // BootstrapFixture::validate(pTempFile->GetFileName(), test::ODF);
+            BootstrapFixture::validate(pTempFile->GetFileName(), test::ODF);
         }
         else if(nExportType == PPTX)
         {