Refactored all pipelines branches to external soft param

Change-Id: I3e451815029227f287aa1575099b0cd25b72433d
diff --git a/jenkins/client/job/deploy/lab/demo.yml b/jenkins/client/job/deploy/lab/demo.yml
index 3ea8a40..2bb6ad5 100644
--- a/jenkins/client/job/deploy/lab/demo.yml
+++ b/jenkins/client/job/deploy/lab/demo.yml
@@ -9,6 +9,7 @@
           scm:
             type: git
             url: "${_param:jenkins_gerrit_url}/mk/mk-pipelines"
+            branch: "${_param:jenkins_pipelines_branch}"
             credentials: "gerrit"
             script: kafka-demo.groovy
           param: