Restore symmetric VKey referenced by BillingEvent.Cancellation (#928)

db/src/main/resources/sql/flyway/V84__add_vkey_columns_in_billing_cancellation.sql

@@ -0,0 +1,22 @@
+-- Copyright 2021 The Nomulus Authors. All Rights Reserved.
+--
+-- Licensed under the Apache License, Version 2.0 (the "License");
+-- you may not use this file except in compliance with the License.
+-- You may obtain a copy of the License at
+--
+--     http://www.apache.org/licenses/LICENSE-2.0
+--
+-- Unless required by applicable law or agreed to in writing, software
+-- distributed under the License is distributed on an "AS IS" BASIS,
+-- WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+-- See the License for the specific language governing permissions and
+-- limitations under the License.
+
+alter table "BillingCancellation"
+    add column if not exists "billing_event_history_id" int8;
+alter table "BillingCancellation"
+    add column if not exists "billing_event_domain_repo_id" text;
+alter table "BillingCancellation"
+    add column if not exists "billing_recurrence_history_id" int8;
+alter table "BillingCancellation"
+    add column if not exists "billing_recurrence_domain_repo_id" text;