Fixed ProcessByBrick unitTest. It is now the responsibility of Process...

Fixed ProcessByBrick unitTest.  It is now the responsibility of Process callers to clean-up cubes allocated on their end and passed into Process, as Process will only delete cubes it created itself from filenames or parameter names.

git-svn-id: http://subversion.wr.usgs.gov/repos/prog/isis3/trunk@4139 41f8697f-d340-4b68-9986-7bafba869bb8