Add license and copyright information

Add license information and copyright notice to the cloudbuild.yaml file.

Author: chandra-siri

storage/cloudbuild/zb-system-tests-cloudbuild.yaml

@@ -1,3 +1,17 @@
+# Copyright 2026 Google Inc. 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.
+
 substitutions:
   _REGION: "us-central1"
   _ZONE: "us-central1-a"