Fix old license that snuck into repo (#20702)

Summary:
Quick trivial PR to add back a necessary header. Fixes CI as well.
Pull Request resolved: https://github.com/facebook/react-native/pull/20702

Differential Revision: D9374430

Pulled By: hramos

fbshipit-source-id: dba0f1d4fc80e39242d8c3e6d1e0007492d2860d

React/Views/RCTWKWebView.h

@@ -1,10 +1,8 @@
 /**
  * Copyright (c) 2015-present, Facebook, Inc.
- * All rights reserved.
  *
- * This source code is licensed under the BSD-style license found in the
- * LICENSE file in the root directory of this source tree. An additional grant
- * of patent rights can be found in the PATENTS file in the same directory.
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
  */
 
 #import <React/RCTView.h>

React/Views/RCTWKWebView.m

@@ -1,3 +1,10 @@
+/**
+ * Copyright (c) 2015-present, Facebook, Inc.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
 #import "RCTWKWebView.h"
 #import <React/RCTConvert.h>
 #import "RCTAutoInsetsProtocol.h"

React/Views/RCTWKWebViewManager.h

@@ -1,4 +1,9 @@
-// Copyright 2004-present Facebook. All Rights Reserved.
+/**
+ * Copyright (c) 2015-present, Facebook, Inc.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
 
 #import <React/RCTViewManager.h>
 

React/Views/RCTWKWebViewManager.m

@@ -1,3 +1,10 @@
+/**
+ * Copyright (c) 2015-present, Facebook, Inc.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
 #import "RCTWKWebViewManager.h"
 
 #import "RCTUIManager.h"