Add missing tfvars template to the tfc blueprint

blueprints/cloud-operations/terraform-cloud-dynamic-credentials/gcp-workload-identity-provider/terraform.auto.tfvars.template

@@ -0,0 +1,18 @@
+# Copyright 2023 Google LLC
+#
+# 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
+#
+#     https://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.
+
+billing_account = "015647-1A8CBC-A002D9"
+parent = "folders/0123456789"
+tfc_organization_id = "org-W3bx9naazHrUz99U"
+tfc_workspace_id = "ws-2GnGJtqTfvxKptHn"