Remove react-native.js.flow

Summary:
We've enabled getters in .flowconfig, so Flow will now understand react-native.js. We no longer need to maintain a separate file for Flow.

cc bestander
Closes https://github.com/facebook/react-native/pull/9892

Differential Revision: D3862560

Pulled By: bestander

fbshipit-source-id: 9efb66bc885dbac80c18b4b5e3cf5362495928a9

Examples/UIExplorer/js/ModalExample.js

@@ -33,7 +33,7 @@ var {
   TouchableHighlight,
   View,
 } = ReactNative;
-// $FlowFixMe Picker.Item not properly defined for flow.
+
 const Item = Picker.Item;
 
 exports.displayName = (undefined: ?string);

Examples/UIExplorer/js/NativeAnimationsExample.js

@@ -50,7 +50,6 @@ class Tester extends React.Component {
       toValue: this.current,
     };
 
-    // $FlowIssue #0000000
     Animated[this.props.type](this.state.native, { ...config, useNativeDriver: true }).start();
     Animated[this.props.type](this.state.js, { ...config, useNativeDriver: false }).start();
   };

Examples/UIExplorer/js/PickerExample.js

@@ -33,7 +33,7 @@ const {
   Text,
   TouchableWithoutFeedback,
 } = ReactNative;
-// $FlowFixMe found when converting React.createClass to ES6
+
 const Item = Picker.Item;
 
 class PickerExample extends React.Component {

Examples/UIExplorer/js/SwipeableListViewExample.js

@@ -66,9 +66,7 @@ var SwipeableListViewSimpleExample = React.createClass({
           dataSource={this.state.dataSource}
           maxSwipeDistance={100}
           renderQuickActions={
-            /* $FlowFixMe(>=0.31.0) */
             (rowData: Object, sectionID: string, rowID: string) => {
-            /* $FlowFixMe(>=0.31.0) */
             return (<View style={styles.actionsContainer}>
               <TouchableHighlight onPress={() => {
                 Alert.alert('Tips', 'You could do something with this row: ' + rowData.text);