Add support for Aodh alarming endpoints

Aodh is part of the OpenStack Telemetry and provides alarming and
notification services based on events across an OpenStack Cloud.

Ensure that keystone understands 'aodh' and 'alarming' as valid
endpoint types.

Change-Id: Id1d9fed86ec7af2327f2d18738703290b4f833a1

hooks/keystone_utils.py

@@ -304,6 +304,10 @@ valid_services = {
         "type": "astara",
         "desc": "Astara Network Orchestration Service",
     },
+    "aodh": {
+        "type": "alarming",
+        "desc": "Aodh Alarming Service",
+    },
 }
 
 # The interface is said to be satisfied if anyone of the interfaces in the