[ML] Give the kibana user read/write access to reindexed hidden ml indices (elastic#121897)

Indices are reindexed on upgrade. Adds an index pattern to the role
descriptor matching the upgraded indices

Author: davidkyle

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

@@ -119,6 +119,11 @@ static RoleDescriptor kibanaSystem(String name) {
                     .indices(".ml-annotations*", ".ml-notifications*")
                     .privileges("read", "write")
                     .build(),
+                // And the reindexed indices from v7
+                RoleDescriptor.IndicesPrivileges.builder()
+                    .indices(".reindexed-v8-ml-annotations*", ".reindexed-v8-ml-notifications*")
+                    .privileges("read", "write")
+                    .build(),
 
                 // APM agent configuration - system index defined in KibanaPlugin
                 RoleDescriptor.IndicesPrivileges.builder()