"As axecuteAndRollbackOperation() result is retrieved but actual rollback of deployment is is not complete."

That's a bug then. Service changes due to rollback should be completed before the operation returns. Please file a JIRA, add a TODO comment in front of this Thread.sleep() referencing that JIRA and indicating the sleep should be removed, and change the commit message for this PR to reference that JIRA. In the JIRA description please reference this Thread.sleep() as reminder to clean it out.