message: Add aria label for support button in mobile, close button in support popover
diff: import { useApp } from '@backstage/core-plugin-api';
  import { BackstageTheme } from '@backstage/theme';
  -import { makeStyles } from '@material-ui/core/styles';
  -import useMediaQuery from '@material-ui/core/useMediaQuery';
  import Box from '@material-ui/core/Box';
  import Button from '@material-ui/core/Button';
  import DialogActions from '@material-ui/core/DialogActions';
  @@ -27,7 +25,9 @@ import ListItem from '@material-ui/core/ListItem';
  import ListItemIcon from '@material-ui/core/ListItemIcon';
  import ListItemText from '@material-ui/core/ListItemText';
  import Popover from '@material-ui/core/Popover';
  +import { makeStyles } from '@material-ui/core/styles';
  import Typography from '@material-ui/core/Typography';
  +import useMediaQuery from '@material-ui/core/useMediaQuery';
  import React, { MouseEventHandler, useState } from 'react';
  import { SupportItem, SupportItemLink, useSupportConfig } from '../../hooks';
  import { HelpIcon } from '../../icons';
  @@ -111,13 +111,14 @@ export function SupportButton(props: SupportButtonProps) {
  size="small"
  onClick={onClickHandler}
  data-testid="support-button"
  + aria-label="Support"
  >
  <HelpIcon />
  </IconButton>
  ) : (
  <Button
  data-testid="support-button"
  - aria-label="support"
  + aria-label="Support"
  color="primary"
  onClick={onClickHandler}
  startIcon={<HelpIcon />}
  @@ -156,7 +157,11 @@ export function SupportButton(props: SupportButtonProps) {
  ))}
  </List>
  <DialogActions>
  - <Button color="primary" onClick={popoverCloseHandler}>
  + <Button
  + color="primary"
  + onClick={popoverCloseHandler}
  + aria-label="Close"
  + >
  Close
  </Button>
  </DialogActions>
  