DERBY-6434: Don't make INSERT statements require USAGE privilege on the datatypes of generated columns; fix remaining problem described by DERBY-6433; commit derby-6434-04-aa-dontNeedPrivOnGeneratedColumnTypeForInsert.diff.

git-svn-id: https://svn.apache.org/repos/asf/db/derby/code/trunk@1558559 13f79535-47bb-0310-9956-ffa450edef68