(charmed-osm) Add auth to prometheus and update kafka/zk

- Authentication to prometheus:
  - Update prometheus relation to provide auth credentials (user/pass)
  - Update grafana datasource to include credentials to prometheus
- Update kafka and zookeeper charms:
  - Add support for the charms to talk to the new kafka charm
  - Add kafka and zookeeper charms in local bundle

Change-Id: Ifb83769583178f3a2069ae6756aa430ec69eecce
Signed-off-by: David Garcia <david.garcia@canonical.com>
diff --git a/installers/charm/ro/src/charm.py b/installers/charm/ro/src/charm.py
index 2a8c110..67ba518 100755
--- a/installers/charm/ro/src/charm.py
+++ b/installers/charm/ro/src/charm.py
@@ -168,7 +168,10 @@
         missing_relations = []
 
         if config.enable_ng_ro:
-            if self.kafka_client.is_missing_data_in_unit():
+            if (
+                self.kafka_client.is_missing_data_in_unit()
+                and self.kafka_client.is_missing_data_in_app()
+            ):
                 missing_relations.append("kafka")
             if not config.mongodb_uri and self.mongodb_client.is_missing_data_in_unit():
                 missing_relations.append("mongodb")