chore: update react imports

Signed-off-by: Paul Schultz <pschultz@pobox.com>

plugins/app-visualizer/src/components/AppVisualizerPage/AppVisualizerPage.tsx

@@ -18,7 +18,7 @@ import { Content, Header, HeaderTabs, Page } from '@backstage/core-components';
 import { useApi } from '@backstage/core-plugin-api';
 import { appTreeApiRef } from '@backstage/frontend-plugin-api';
 import Box from '@material-ui/core/Box';
-import React, { useCallback, useEffect, useMemo } from 'react';
+import { useCallback, useEffect, useMemo } from 'react';
 import { DetailedVisualizer } from './DetailedVisualizer';
 import { TextVisualizer } from './TextVisualizer';
 import { TreeVisualizer } from './TreeVisualizer';

plugins/app-visualizer/src/components/AppVisualizerPage/DetailedVisualizer.tsx

@@ -33,7 +33,6 @@ import * as colors from '@material-ui/core/colors';
 import { makeStyles } from '@material-ui/core/styles';
 import InputIcon from '@material-ui/icons/InputSharp';
 import DisabledIcon from '@material-ui/icons/NotInterestedSharp';
-import React from 'react';
 import { Link } from 'react-router-dom';
 
 function createOutputColorGenerator(

plugins/app-visualizer/src/components/AppVisualizerPage/TextVisualizer.tsx

@@ -19,7 +19,7 @@ import Box from '@material-ui/core/Box';
 import Checkbox from '@material-ui/core/Checkbox';
 import FormControlLabel from '@material-ui/core/FormControlLabel';
 import Paper from '@material-ui/core/Paper';
-import React, { ReactNode, useState } from 'react';
+import { ReactNode, useState } from 'react';
 
 function mkDiv(
   children: ReactNode,

plugins/app-visualizer/src/components/AppVisualizerPage/TreeVisualizer.tsx

@@ -14,7 +14,6 @@
  * limitations under the License.
  */
 
-import React from 'react';
 import {
   DependencyGraph,
   DependencyGraphTypes,

plugins/app-visualizer/src/plugin.tsx

@@ -21,7 +21,6 @@ import {
   PageBlueprint,
 } from '@backstage/frontend-plugin-api';
 import VisualizerIcon from '@material-ui/icons/Visibility';
-import React from 'react';
 
 const rootRouteRef = createRouteRef();