[Fleet] added privileges for fleet-synced-integrations (#121753)

* added privileges for fleet-synced-integrations

* Update index-templates.asciidoc

* Revert "Update index-templates.asciidoc"

This reverts commit b73bae8.

Author: juliaElastic

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

@@ -229,6 +229,11 @@ static RoleDescriptor kibanaSystem(String name) {
                 RoleDescriptor.IndicesPrivileges.builder().indices("metrics-fleet_server*").privileges("all").build(),
                 // Fleet reads output health from this index pattern
                 RoleDescriptor.IndicesPrivileges.builder().indices("logs-fleet_server*").privileges("read", "delete_index").build(),
+                // Fleet creates and writes this index for sync integrations feature
+                RoleDescriptor.IndicesPrivileges.builder()
+                    .indices("fleet-synced-integrations")
+                    .privileges("create_index", "manage", "read", "write")
+                    .build(),
                 // Legacy "Alerts as data" used in Security Solution.
                 // Kibana user creates these indices; reads / writes to them.
                 RoleDescriptor.IndicesPrivileges.builder()