Add 'get_variable_from_url' option for job parameters in Workflow.groovy

Use the actual artifact content as a job parameter
instead of the artifact's URL.

With 'get_variable_from_url', content will be downloaded from the
artifact's URL and placed into the job parameter value.

https://mirantis.jira.com/browse/PROD-33442

Change-Id: I6c9bfaec74688979202e904734f77160901f7adb
1 file changed