Fix PLA relations, add missing ENVs, and include it in the bundle

Change-Id: I4d309d045404a900e04909c46196d32e43bb1862
Signed-off-by: David Garcia <david.garcia@canonical.com>
diff --git a/installers/charm/pla/metadata.yaml b/installers/charm/pla/metadata.yaml
index 37b6214..afd4574 100644
--- a/installers/charm/pla/metadata.yaml
+++ b/installers/charm/pla/metadata.yaml
@@ -26,6 +26,6 @@
   kafka:
     interface: kafka
   mongo:
-    interface: mongo
+    interface: mongodb
   mysql:
     interface: mysql
\ No newline at end of file