Use mongodb charm in k8s installer

- Update JUJU_AGENT_VERSION to 2.8.6
- Use mongodb charm and update needed osm pod specs to point at it

Change-Id: I75734a19aaa5b3b7a8913591ee86a8e1b82b29cd
Signed-off-by: David Garcia <david.garcia@canonical.com>
Signed-off-by: garciadeblas <gerardo.garciadeblas@telefonica.com>
diff --git a/installers/docker/osm_pods/nbi.yaml b/installers/docker/osm_pods/nbi.yaml
index c1fbf30..0dd2b2d 100644
--- a/installers/docker/osm_pods/nbi.yaml
+++ b/installers/docker/osm_pods/nbi.yaml
@@ -55,17 +55,17 @@
         - containerPort: 9999
           protocol: TCP
         env:
-         - name: OSMNBI_DATABASE_HOST
-           value: mongodb-k8s
-         - name:  OSMNBI_MESSAGE_HOST
-           value: kafka
+        - name: OSMNBI_DATABASE_URI
+          value: mongodb://mongodb-k8s:27017/?replicaSet=rs0
+        - name:  OSMNBI_MESSAGE_HOST
+          value: kafka
         envFrom:
         - secretRef:
-           name: nbi-secret
+          name: nbi-secret
         volumeMounts:
-         - name: osm-packages
-           mountPath: /app/storage
+        - name: osm-packages
+          mountPath: /app/storage
       volumes:
-       - name: osm-packages
-         hostPath:
+      - name: osm-packages
+        hostPath:
           path: /var/lib/osm/osm_osm_packages/_data