Add gitRef parameter to checkoutReleaseMetadataRepo() function

It should allow to checkout specific git reference instead of just branch

Change-Id: I89de1626a29b2713952e84175e393c2748692472
Related-Prod: PROD-31595
diff --git a/src/com/mirantis/mk/ReleaseWorkflow.groovy b/src/com/mirantis/mk/ReleaseWorkflow.groovy
index efc588b..7da212d 100644
--- a/src/com/mirantis/mk/ReleaseWorkflow.groovy
+++ b/src/com/mirantis/mk/ReleaseWorkflow.groovy
@@ -15,18 +15,19 @@
     String gitCredentialsId = params.get('metadataCredentialsId', 'mcp-ci-gerrit')
     String gitUrl           = params.get('metadataGitRepoUrl', "ssh://${gitCredentialsId}@gerrit.mcp.mirantis.net:29418/mcp/release-metadata")
     String gitBranch        = params.get('metadataGitRepoBranch', 'master')
+    String gitRef           = params.get('metadataGitRepoRef', '')
     String repoDir          = params.get('repoDir', 'release-metadata')
-    if (cloneRepo){
+    if (cloneRepo) {
         stage('Cleanup repo dir') {
             dir(repoDir) {
                 deleteDir()
             }
         }
         stage('Cloning release-metadata repository') {
-            git.checkoutGitRepository(repoDir, gitUrl, gitBranch, gitCredentialsId, true, 10, 0)
+            git.checkoutGitRepository(repoDir, gitUrl, gitBranch, gitCredentialsId, true, 10, 0, gitRef)
         }
     } else {
-        git.changeGitBranch(repoDir, gitBranch)
+        git.changeGitBranch(repoDir, gitRef ?: gitBranch)
     }
 }
 
@@ -154,4 +155,4 @@
         //post change
         gerrit.postGerritReview(credentialsID, venvDir, repoDir, changeAuthorName, changeAuthorEmail, gitRemote, crTopic, metadataGerritBranch)
     }
-}
\ No newline at end of file
+}