[Fleet] Add permissions to kibana_system to write logs-elastic_agent.status_change-* data stream (#129191)

* Update KibanaOwnedReservedRoleDescriptors.java

* Update KibanaOwnedReservedRoleDescriptors.java

Author: juliaElastic

x-pack/plugin/core/src/main/java/org/elasticsearch/xpack/core/security/authz/store/KibanaOwnedReservedRoleDescriptors.java

@@ -223,6 +223,8 @@ static RoleDescriptor kibanaSystem(String name) {
                     .privileges("all")
                     .allowRestrictedIndices(true)
                     .build(),
+                // Fleet writes to this datastream for Agent status alerting feature
+                RoleDescriptor.IndicesPrivileges.builder().indices("logs-elastic_agent.status_change-*").privileges("all").build(),
                 // Fleet telemetry queries Agent Logs indices in kibana task runner
                 RoleDescriptor.IndicesPrivileges.builder().indices("logs-elastic_agent*").privileges("read").build(),
                 // Fleet publishes Agent metrics in kibana task runner