Introducing variables in Jenkinsfile for automated POD build

Change-Id: I158cd91dc517f232a5d1b1126234c36626d3387d
diff --git a/Jenkinsfile b/Jenkinsfile
index 643b3bc..8e5b9f7 100644
--- a/Jenkinsfile
+++ b/Jenkinsfile
@@ -9,7 +9,7 @@
 }
 
 timeout (time: 240) {
-    node ('build') {
+    node ('${devNodeJenkinsName}') {
        stage 'Checkout cord repo'
        checkout changelog: false, poll: false, scm: [$class: 'RepoScm', currentBranch: true, manifestBranch: params.branch, manifestRepositoryUrl: 'https://gerrit.opencord.org/manifest', quiet: true]