Add copyrights

Author: lfkellogg

firebase-appdistribution/src/main/java/com/google/firebase/appdistribution/impl/ApkHashExtractor.java

@@ -1,3 +1,17 @@
+// Copyright 2022 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
+//
+//      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.
+
 package com.google.firebase.appdistribution.impl;
 
 import static com.google.firebase.appdistribution.impl.ReleaseIdentificationUtils.getPackageInfoWithMetadata;

firebase-appdistribution/src/test/java/com/google/firebase/appdistribution/impl/ApkHashExtractorTest.java

@@ -1,3 +1,17 @@
+// Copyright 2022 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
+//
+//      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.
+
 package com.google.firebase.appdistribution.impl;
 
 import static com.google.common.truth.Truth.assertThat;