Update bundle (standalone and HA) to use MongoDB charm from edge channel

Change-Id: Ie60a105a58c5838db90129f1d6d896907675a405
Signed-off-by: Dario Faccin <dario.faccin@canonical.com>
diff --git a/installers/charm/bundles/osm-ha/bundle.yaml b/installers/charm/bundles/osm-ha/bundle.yaml
index 166cb00..2b64762 100644
--- a/installers/charm/bundles/osm-ha/bundle.yaml
+++ b/installers/charm/bundles/osm-ha/bundle.yaml
@@ -55,7 +55,7 @@
       ha-mode: true
   mongodb:
     charm: mongodb-k8s
-    channel: latest/stable
+    channel: latest/edge
     scale: 3
     series: kubernetes
     storage: