Replace our local types by flow-typed (#20320)

Summary:
These comments were confusing since we don't use flow-typed.

cc bvaughn.

I have replaced our local types by flow-typed, removed metro custom stub and deleted `flow-github` directory.

As result, createReactClass, PropTypes and Metro types won't be distributed to RN users. If you need it, you should relay on flow-typed.
Pull Request resolved: https://github.com/facebook/react-native/pull/20320

Reviewed By: TheSavior

Differential Revision: D13517157

Pulled By: rickhanlonii

fbshipit-source-id: e52c0b6114114a706f6152b2031c600e3dece0d2

.flowconfig

@@ -31,7 +31,6 @@
 [libs]
 Libraries/react-native/react-native-interface.js
 flow/
-flow-github/
 
 [options]
 emoji=true

.flowconfig.android

@@ -31,7 +31,6 @@
 [libs]
 Libraries/react-native/react-native-interface.js
 flow/
-flow-github/
 
 [options]
 emoji=true

flow-github/metro.js

@@ -1,15 +0,0 @@
-/**
- * Copyright (c) Facebook, Inc. and its affiliates.
- *
- * This source code is licensed under the MIT license found in the
- * LICENSE file in the root directory of this source tree.
- *
- * @flow
- * @format
- */
-
-// metro-visualizer is not listed as a dependency of metro since it pulls a lot
-// of transitive dependencies so we need to tell flow that it may exist.
-declare module 'metro-visualizer' {
-  declare module.exports: any;
-}

flow-typed/npm/create-react-class_v15.x.x.js

@@ -9,7 +9,8 @@
  * @nolint
  */
 
-// TODO (acdlite) Remove this file once flowtype/flow-typed/pull/773 is merged
+// flow-typed signature: 892fd8dcd3f17e76da4fb1334b0fd49e
+// flow-typed version: da30fe6876/create-react-class_v15.x.x/flow_>=v0.41.x
 
 declare module 'create-react-class' {
   declare module.exports: React$CreateClass;

flow-typed/npm/prop-types_v15.x.x.js

@@ -9,7 +9,8 @@
  * @format
  */
 
-// TODO (bvaughn) Remove this file once flowtype/flow-typed/pull/773 is merged
+// flow-typed signature: d9a983bb1ac458a256c31c139047bdbb
+// flow-typed version: 927687984d/prop-types_v15.x.x/flow_>=v0.41.x
 
 type $npm$propTypes$ReactPropsCheckType = (
   props: any,
@@ -25,6 +26,7 @@ declare module 'prop-types' {
   declare var number: React$PropType$Primitive<number>;
   declare var object: React$PropType$Primitive<Object>;
   declare var string: React$PropType$Primitive<string>;
+  declare var symbol: React$PropType$Primitive<Symbol>;
   declare var any: React$PropType$Primitive<any>;
   declare var arrayOf: React$PropType$ArrayOf;
   declare var element: React$PropType$Primitive<any>; /* TODO */

package.json

@@ -104,7 +104,6 @@
     "android",
     "cli.js",
     "flow",
-    "flow-github",
     "init.sh",
     "scripts/ios-configure-glog.sh",
     "scripts/ios-install-third-party.sh",

template/_flowconfig

@@ -24,7 +24,6 @@
 [libs]
 node_modules/react-native/Libraries/react-native/react-native-interface.js
 node_modules/react-native/flow/
-node_modules/react-native/flow-github/
 
 [options]
 emoji=true