Pass the deployment variables automatically into environment variables (like build/plan/global variables do)

Steps to reproduce:

1) create a script task in the deployment project with the below contents:

!#/bin/bash

echo "---- BEGIN ENVIRONMENT VARIABLES ----"
/usr/bin/env
echo "---- END ENVIRONMENT VARIABLES ----"

2) run the deployment
3a) expected result (in the logs) is to see all the deployment variables in addition to the build variables. At the moment, it shows only the environment and build/global variables

But we don't do that for built-in variables like:

• ${bamboo.deploy.environment}
• ${bamboo.deploy.project}
• ${bamboo.deploy.rollback}
• ${bamboo.deploy.release}
  etc...