Update strings.xml

fix header

Author: codingjeremy

ActivitySceneTransitionBasic/app/src/main/res/values/strings.xml

@@ -1,4 +1,5 @@
-<?xml version="1.0" encoding="utf-8"?><!-- Copyright (C) 2014 The Android Open Source Project
+<?xml version="1.0" encoding="utf-8"?>
+<!-- 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.