MB-12274: Adding rel-2.5.2.xml

Currently same content as rel-2.5.1.xml.

Change-Id: Id1dff3a245d90ab3e2f673a05d304cb3649c6c22
Reviewed-on: http://review.couchbase.org/43268
Reviewed-by: Chris Hillery <ceej@couchbase.com>
Tested-by: Chris Hillery <ceej@couchbase.com>