OpenXMLFilter: "Translate Document Properties" doesn't work for Excel files

Created by: Anonymous

Original issue 451 created by @ysavourel on 2015-03-18T18:28:58.000Z:

For other file types, this option exposes the contents of the docProps/core.xml file. However, for Excel this content isn't exposed.

A sample file (with the creator "Chase Tingley" in the docprops) is attached.