DERBY-5630; intermittent test failure in store/lockTableVTI.sql
  backport of revisions 1564608 and 1564635 from trunk, converting the test to junit for better control


git-svn-id: https://svn.apache.org/repos/asf/db/derby/code/branches/10.10@1565415 13f79535-47bb-0310-9956-ffa450edef68