Change icons in web UI (#27385)

Co-authored-by: Renaud Chaput <renchap@gmail.com>

app/javascript/mastodon/features/compose/components/poll_button.jsx

@@ -3,8 +3,11 @@ import { PureComponent } from 'react';
 
 import { defineMessages, injectIntl } from 'react-intl';
 
+import { ReactComponent as InsertChartIcon } from '@material-symbols/svg-600/outlined/insert_chart.svg';
+
 import { IconButton } from '../../../components/icon_button';
 
+
 const messages = defineMessages({
   add_poll: { id: 'poll_button.add_poll', defaultMessage: 'Add a poll' },
   remove_poll: { id: 'poll_button.remove_poll', defaultMessage: 'Remove poll' },
@@ -40,6 +43,7 @@ class PollButton extends PureComponent {
       <div className='compose-form__poll-button'>
         <IconButton
           icon='tasks'
+          iconComponent={InsertChartIcon}
           title={intl.formatMessage(active ? messages.remove_poll : messages.add_poll)}
           disabled={disabled}
           onClick={this.handleClick}