Update gerrit credentials value in vnf jobs

PROD-31174

Change-Id: I0836fe9896f0f9189fd83221233cd827ee94a0fe
diff --git a/jenkins/client/job/git-mirrors/downstream/init.yml b/jenkins/client/job/git-mirrors/downstream/init.yml
index 39aaa5f..92a3d6d 100644
--- a/jenkins/client/job/git-mirrors/downstream/init.yml
+++ b/jenkins/client/job/git-mirrors/downstream/init.yml
@@ -19,7 +19,7 @@
               type: git
               url: "${_param:jenkins_gerrit_url}/mk/mk-pipelines"
               branch: "${_param:jenkins_pipelines_branch}"
-              credentials: ${_param:jenkins_gerrit_credentials}
+              credentials: "${_param:jenkins_gerrit_credentials}"
               script: git-mirror-pipeline.groovy
             param:
               SOURCE_URL:
@@ -33,7 +33,7 @@
                 default: "${_param:jenkins_gerrit_url}/{{downstream}}"
               CREDENTIALS_ID:
                 type: string
-                default: "gerrit"
+                default: ${_param:jenkins_gerrit_credentials}
               BRANCHES:
                 type: string
                 default: "{{branches}}"