The situation is similar to commit
79fb61ef (tdf#92379: svx: don't
overwrite fo:background-color on ODF import, 2015-08-21), except that
here text frames had the problem of loosing colors when transparency is
set.

Fix the problem by informing getSvxBrushItemFromSourceSet() about if
we're in XML import or not.

(cherry picked from commit 3a0c0af7)

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

Change-Id: Id1adf60b14a3762f0a2a43c49caeed9f6ea039be
Reviewed-on: https://gerrit.libreoffice.org/20744Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Andras Timar <andras.timar@collabora.com>
(cherry picked from commit 09ea045d)