Update build_all_linux_artifacts.sh

packages/grpc-native-core/tools/run_tests/artifacts/build_all_linux_artifacts.sh

@@ -1,4 +1,17 @@
 #!/bin/bash
+# Copyright 2017 gRPC authors.
+#
+# 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.
 
 [ -s "$NVM_DIR/nvm.sh" ] && . "$NVM_DIR/nvm.sh"
 nvm install 10