CBQE-0: Collect data files for xdcr upgrade tests too

Change-Id: I3aa08fa5abbc61f0f92ce1aec92869931c429d7f
Reviewed-on: http://review.couchbase.org/39154
Reviewed-by: Sangharsh Agarwal <sangharsh.agarwal@globallogic.com>
Tested-by: Sangharsh Agarwal <sangharsh.agarwal@globallogic.com>