Update COO sub to stable channel

Author: vyzigold

roles/openshift_obs/defaults/main.yml

@@ -24,7 +24,7 @@ cifmw_openshift_obs_definition:
     labels:
       operators.coreos.com/observability-operator.openshift-operators: ""
   spec:
-    channel: development
+    channel: stable
     installPlanApproval: Automatic
     name: cluster-observability-operator
     source: redhat-operators