BUG: Fix vtkSlicerDoubleArraysLogicAddFileTest

Created by: jcfr

WIP DO NOT INTEGRATE

This commit fixes test vtkSlicerDoubleArraysLogicAddFileTest to account for commit introduced in r24675 (BUG: Fix support for missing labels in vtkMRMLDoubleArrayStorage reader)

At time of integration, only the test vtkMRMLDoubleArrayStorageNodeTest1 updated in r24676 (ENH: Add test for vtkMRMLDoubleArrayStorageNode reader/writer) has been executed to confirm it was working.

Failure reported on the dashboard:

• Linux: http://slicer.cdash.org/testDetails.php?test=6885663&build=700523
• MacOSX: http://slicer.cdash.org/testDetails.php?test=6885265&build=700522
• Windows: http://slicer.cdash.org/testDetails.php?test=6886406&build=700521