Prepare React imports for Jest

Summary:
Not sure if it's Metro or something else providing these globally,
but it makes Jest unhappy if they're missing.

Reviewed By: danielbuechele

Differential Revision: D9788350

fbshipit-source-id: 5fabad7af146bcb705471d2c7e66d79265c81c82

src/device-plugins/logs/index.js

@@ -15,6 +15,7 @@ import type {Counter} from './LogWatcher.js';
 import type {DeviceLogEntry} from '../../devices/BaseDevice.js';
 import type {Props as PluginProps} from '../../plugin';
 
+import * as React from 'react';
 import {
   Text,
   ManagedTable,
@@ -24,9 +25,10 @@ import {
   FlexColumn,
   Glyph,
   SonarSidebar,
+  SonarDevicePlugin,
+  SearchableTable,
   styled,
 } from 'sonar';
-import {SonarDevicePlugin, SearchableTable} from 'sonar';
 import textContent from '../../utils/textContent.js';
 import createPaste from '../../utils/createPaste.js';
 import LogWatcher from './LogWatcher';

src/ui/components/Button.js

@@ -5,13 +5,14 @@
  * @format
  */
 
+import * as React from 'react';
 import Glyph from './Glyph.js';
-import styled from '../styled/index.js';
-import {findDOMNode} from 'react-dom';
 import PropTypes from 'prop-types';
+import electron from 'electron';
+import styled from '../styled/index.js';
 import {colors} from './colors.js';
 import {connect} from 'react-redux';
-import electron from 'electron';
+import {findDOMNode} from 'react-dom';
 import {keyframes} from 'react-emotion';
 
 const borderColor = props => {

src/ui/components/ContextMenu.js

@@ -5,6 +5,7 @@
  * @format
  */
 
+import * as React from 'react';
 import FlexColumn from './FlexColumn.js';
 import PropTypes from 'prop-types';