AWS Cloudformation template - Update ENV variables

Hello I used the AWS Cloud-formation template to install kong v2.1 on EC2 instance.

And I want to set

server_tokens = off

latency_tokens = off

I see in the template that there is a param called KongConfigs so if I just write the below will this disable the above?

KONG_HEADERS='' (empty value)

Also

When am running

env command on the instance I dont see any of the following env variables

KONG_PG_HOST
KONG_PG_PORT

Why is this happening?