Provide the way to set env variable to deployment config of integration pod

(Migrated from https://github.com/syndesisio/syndesis/issues/4634)

Author: Abdellatif BOUCHAMA
Assignees: Dhiraj Bokde,
(Placeholder for https://issues.jboss.org/browse/ENTESB-10194)

When we set a new environment variable, by default the deployment config starts new deployment,
After that, when we edit the integration flow in Syndesis Dashboard -> No Action will be performed and the Status will be reflected as "?" near the Integration name.