Add license header to github workflow files

Unfortunately, we need them here also.

PiperOrigin-RevId: 279427268
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 07be78d..5ea2e83 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -1,3 +1,17 @@
+# Copyright 2019 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.
+
 name: Continuous Integration
 
 on:
diff --git a/.github/workflows/presubmit.yml b/.github/workflows/presubmit.yml
index bbe3bdd..f9689e9 100644
--- a/.github/workflows/presubmit.yml
+++ b/.github/workflows/presubmit.yml
@@ -1,3 +1,17 @@
+# Copyright 2019 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.
+
 name: Presubmits
 
 on: