fix: update selection icons (plus and minus)

Author: dcoa

src/course-home/outline-tab/Section.jsx

@@ -2,11 +2,11 @@ import React, { useEffect, useState } from 'react';
 import PropTypes from 'prop-types';
 import { injectIntl, intlShape } from '@edx/frontend-platform/i18n';
 import { Collapsible, IconButton, Icon } from '@openedx/paragon';
-import { faCheckCircle as fasCheckCircle, faMinus, faPlus } from '@fortawesome/free-solid-svg-icons';
+import { faCheckCircle as fasCheckCircle } from '@fortawesome/free-solid-svg-icons';
 import { faCheckCircle as farCheckCircle } from '@fortawesome/free-regular-svg-icons';
 import { FontAwesomeIcon } from '@fortawesome/react-fontawesome';
 
-import { DisabledVisible } from '@openedx/paragon/icons';
+import { Add, DisabledVisible, Minus } from '@openedx/paragon/icons';
 import SequenceLink from './SequenceLink';
 import { useModel } from '../../generic/model-store';
 
@@ -96,15 +96,15 @@ const Section = ({
         iconWhenClosed={(
           <IconButton
             alt={intl.formatMessage(messages.openSection)}
-            icon={faPlus}
+            iconAs={Add}
             onClick={() => { setOpen(true); }}
             size="sm"
           />
         )}
         iconWhenOpen={(
           <IconButton
             alt={intl.formatMessage(genericMessages.close)}
-            icon={faMinus}
+            iconAs={Minus}
             onClick={() => { setOpen(false); }}
             size="sm"
           />