Disable histogram UDA test for decimal vals due to IMPALA-1111

Change-Id: I21391e671896c9ebe52fd45accc2d290267ee0ac
Reviewed-on: http://gerrit.sjc.cloudera.com:8080/3641
Reviewed-by: Ishaan Joshi <ishaan@cloudera.com>
Tested-by: jenkins
(cherry picked from commit 5a7ede02ffda4bdbbde4bc56184639fdee0a9857)
Reviewed-on: http://gerrit.sjc.cloudera.com:8080/3652
Reviewed-by: Matthew Jacobs <mj@cloudera.com>