add option to specify ec2 tag collection

issue opened on chef-datadog: https://github.com/DataDog/chef-datadog/issues/158

I have 2 opsworks stack and in order for me to differentiate between them I need to be able to collect the ec2 tags associated with the machine.
if I manually set 
collect_ec2_tags: no
in /etc/dd-agent/datadog.conf I can see the tags being collected.

When I run the chef recipe via opsworks though, I don't see this parameter being configured in datadog.conf 
Looking at the template erg seems that the param is not there.

Added ['datadog']['collect_ec2_tags'] and ['datadog']['api_key'] to the custom json used by opsworks and the api_key is picked up just fine (i see it ending up in config) but the collect_ec2_tags is just ignored.

Need to find a way to add collecting the ec2 tags in config when the agent is installed via chef (or an workaround)