Update helper scripts

Signed-off-by: Alexey Polyudov <apolyudov@google.com>
Change-Id: Ibaa0221a6cf55775f882d7888272e317ae3e2298

script/handle_oss.sh

@@ -18,3 +18,5 @@
 ./oss.py --all --no-subst --fix-oss-headers .
 ./oss.py --all --google3-filter --no-subst --fix-oss-headers --no-recurse ..
 ./oss.py --google3-filter --fix-oss-headers --proto-lite-runtime ..
+cd ..
+/google/bin/releases/opensource/thirdparty/cross/cross .

script/oss.py

@@ -1,5 +1,20 @@
 #!/usr/bin/python3
 
+# Copyright 2020 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.
+
+
 import argparse
 import os
 import shutil