DERBY-6623 DatabaseMetaDataTest fails intermittently

Another instance of the test neglecting to consider that the rows may
legimimately come back in another order.  Switched to using
*assertFullUnorderedResultSet* instead of *assertFullResultSet*.

git-svn-id: https://svn.apache.org/repos/asf/db/derby/code/trunk@1615821 13f79535-47bb-0310-9956-ffa450edef68