Prepare installer and pods for Rel TWELVE

Change-Id: I9fa2bfe6322748b9fbd22d2348b88f8f63df0329
Signed-off-by: garciadeblas <gerardo.garciadeblas@telefonica.com>
diff --git a/installers/docker/osm_pods/prometheus.yaml b/installers/docker/osm_pods/prometheus.yaml
index c564759..ac3a524 100644
--- a/installers/docker/osm_pods/prometheus.yaml
+++ b/installers/docker/osm_pods/prometheus.yaml
@@ -128,7 +128,7 @@
         - name: prom-db
           mountPath: /prometheus
       - name: prometheus-config-sidecar
-        image: opensourcemano/prometheus:11
+        image: opensourcemano/prometheus:12
         env:
         - name: MONGODB_URL
           value: mongodb://mongodb-k8s:27017/?replicaSet=rs0