feat(overlays): switch to flow Props

react/features/overlay/components/OverlayContainer.js

-/* global interfaceConfig */
+// @flow
 
-import PropTypes from 'prop-types';
 import React, { Component } from 'react';
 import { connect } from 'react-redux';
 
     from './UserMediaPermissionsFilmstripOnlyOverlay';
 import UserMediaPermissionsOverlay from './UserMediaPermissionsOverlay';
 
+declare var interfaceConfig: Object;
+
 /**
  * The lazily-initialized list of overlay React {@link Component} types used The
  * user interface is filmstrip-only.
 let _nonFilmstripOnlyOverlays;
 
 /**
- * Implements a React {@link Component} that will display the correct overlay
- * when needed.
+ * OverlayContainer component's property types.
  */
-class OverlayContainer extends Component {
+type Props = {
+
     /**
-     * OverlayContainer component's property types.
-     *
-     * @static
+     * Type of overlay that should be rendered.
+     * XXX: We are using 'any' here because overlays are usually wrapped in
+     * functions, so a 'Node' won't do.
      */
-    static propTypes = {
-        /**
-         * Type of overlay that should be rendered.
-         */
-        overlay: PropTypes.element
-    };
+    overlay: any
+}
 
+/**
+ * Implements a React {@link Component} that will display the correct overlay
+ * when needed.
+ */
+class OverlayContainer extends Component<Props> {
     /**
      * Implements React's {@link Component#render()}.
      *