[Security Solution] Add description attribute to the Security grouping of Kibana security sub-feature privileges (#192273)

## Summary

- Adds text under the `security` group that clarifies what actions the
user must do in order to customize the grouping privileges

closes #191592 

<img width="765" alt="image"
src="https://github.com/user-attachments/assets/81f88a59-9e97-4c4d-a5b9-4326d95f8ac5">

x-pack/packages/security-solution/features/src/security/kibana_features.ts

@@ -58,6 +58,13 @@ export const getSecurityBaseKibanaFeature = ({
     insightsAndAlerting: ['triggersActions'],
   },
   alerting: SECURITY_RULE_TYPES,
+  description: i18n.translate(
+    'securitySolutionPackages.features.featureRegistry.securityGroupDescription',
+    {
+      defaultMessage:
+        "Each sub-feature privilege in this group must be assigned individually. Global assignment is only supported if your pricing plan doesn't allow individual feature privileges.",
+    }
+  ),
   privileges: {
     all: {
       app: [APP_ID, CLOUD_POSTURE_APP_ID, CLOUD_DEFEND_APP_ID, 'kibana'],