DERBY-6064: Failures in upgradeTests.Changes10_9 related to index cardinality statistics

Added logic to adjust asserts based on the version of the old database.
The fix affecting the tests is in the released 10.8.3-version of Derby, and
the fix has been backported to older branches back to 10.3.

Patch file: derby-6064-1a-istat_upgrade_test_fixes.diff


git-svn-id: https://svn.apache.org/repos/asf/db/derby/code/trunk@1441923 13f79535-47bb-0310-9956-ffa450edef68