Inject environment variables for a Job

As developer I would like to get the enviroment variables when I'm working with a Job. For that, we have the getEnvironment method, designed for:

Creates an environment variable override for launching processes for this project. This is for process launching outside the build execution (such as polling, tagging, deployment, etc.) that happens in a context of a specific job.

Use case

1. I'm using a Subversion repository
2. My repository URL is parametized, for example: https://server/project1/$MODULE
3. I want to do polling

Use case

1. Validate Subversion repositories when its URL is parametized.

This bug would be solved with this improvement.