Add BACKUP_DIR param to ceph-upgrade job

Change-Id: I542bb64c8bada762ac09dcdc7943f701525c93b7
Related-Prod: PROD-29946
diff --git a/jenkins/client/job/ceph/upgrade.yml b/jenkins/client/job/ceph/upgrade.yml
index 0c07b46..638188e 100644
--- a/jenkins/client/job/ceph/upgrade.yml
+++ b/jenkins/client/job/ceph/upgrade.yml
@@ -73,3 +73,7 @@
               type: boolean
               default: 'true'
               description: Select to copy the disks of Ceph VMs before upgrade and backup Ceph directories on OSD nodes.
+            BACKUP_DIR:
+              type: string
+              default: '/root'
+              description: Select the target dir to backup to when BACKUP_ENABLED