message: Use Backstage progress indicator
diff: @@ -6,9 +6,9 @@ import TableCell from '@material-ui/core/TableCell';
  import TableContainer from '@material-ui/core/TableContainer';
  import TableHead from '@material-ui/core/TableHead';
  import TableRow from '@material-ui/core/TableRow';
  -import LinearProgress from '@material-ui/core/LinearProgress';
  import Alert from '@material-ui/lab/Alert';
  import { useAsync } from 'react-use';
  +import { Progress } from '@spotify-backstage/core';
  const useStyles = makeStyles({
  table: {
  @@ -92,7 +92,7 @@ const ExampleFetchComponent: FC<{}> = () => {
  }, []);
  if (loading) {
  - return <LinearProgress data-testid="progress" />;
  + return <Progress />;
  } else if (error) {
  return <Alert severity="error">{error.message}</Alert>;
  }
  