Fix jsdocs

react/features/base/react/components/native/LoadingIndicator.js

 import { ActivityIndicator } from 'react-native';
 
 /**
- * Simple wrapper around React Native's {@code ActivityIndicator}, which
- * displays an animated (large) loading indicator.
+ * An animated, large react-native {@link ActivityIndicator} which is considered
+ * a suitable visualization of long-running processes with indeterminate amounts
+ * of work to be done.
  */
 export default class LoadingIndicator extends Component {
     /**

react/features/overlay/components/PageReloadFilmstripOnlyOverlay.js

      * Implements React's {@link Component#render()}.
      *
      * @inheritdoc
-     * @returns {ReactElement|null}
+     * @returns {ReactElement}
      */
     render() {
         const { t } = this.props;

react/features/overlay/components/PageReloadOverlay.js

      * Implements React's {@link Component#render()}.
      *
      * @inheritdoc
-     * @returns {ReactElement|null}
+     * @returns {ReactElement}
      */
     render() {
         const { isNetworkFailure, t } = this.props;