Add screensharing behind a feature flag

ts/components/CallingScreenSharingController.stories.tsx

@@ -0,0 +1,29 @@
+// Copyright 2021 Signal Messenger, LLC
+// SPDX-License-Identifier: AGPL-3.0-only
+
+import React from 'react';
+import { storiesOf } from '@storybook/react';
+import { action } from '@storybook/addon-actions';
+
+import {
+  CallingScreenSharingController,
+  PropsType,
+} from './CallingScreenSharingController';
+
+import { setup as setupI18n } from '../../js/modules/i18n';
+import enMessages from '../../_locales/en/messages.json';
+
+const i18n = setupI18n('en', enMessages);
+
+const createProps = (): PropsType => ({
+  i18n,
+  onCloseController: action('on-close-controller'),
+  onStopSharing: action('on-stop-sharing'),
+  presentedSourceName: 'Application',
+});
+
+const story = storiesOf('Components/CallingScreenSharingController', module);
+
+story.add('Controller', () => {
+  return <CallingScreenSharingController {...createProps()} />;
+});