CBQE-812: Random values for templates

- Consider case when parameter is unicode

Change-Id: Id7be932498f5cd3f5775e255e025bdd50e7c048b
Reviewed-on: http://review.couchbase.org/24438
Reviewed-by: abhinav dangeti <abhinav.dangeti@gmail.com>
Tested-by: abhinav dangeti <abhinav.dangeti@gmail.com>