Final changes to config sub-system (#8600)

- Introduces changes such as certain types of
  errors that can be ignored or which need to 
  go into safe mode.
- Update help text as per the review

cmd/config/policy/opa/config.go

@@ -41,10 +41,6 @@ const (
 // DefaultKVS - default config for OPA config
 var (
 	DefaultKVS = config.KVS{
-		config.KV{
-			Key:   config.State,
-			Value: config.StateOff,
-		},
 		config.KV{
 			Key:   URL,
 			Value: "",
@@ -112,6 +108,11 @@ type Opa struct {
 	client *http.Client
 }
 
+// Enabled returns if opa is enabled.
+func Enabled(kvs config.KVS) bool {
+	return kvs.Get(URL) != ""
+}
+
 // LookupConfig lookup Opa from config, override with any ENVs.
 func LookupConfig(kv config.KVS, transport *http.Transport, closeRespFn func(io.ReadCloser)) (Args, error) {
 	args := Args{}