FRE-600: Fix code review blockers

- Consolidated duplicate UndoManagers to single instance
- Fixed connection promise to only resolve on 'connected' status
- Fixed WebSocketProvider import (WebsocketProvider)
- Added proper doc.destroy() cleanup
- Renamed isPresenceInitialized property to avoid conflict

Co-Authored-By: Paperclip <noreply@paperclip.ing>

node_modules/react-native/Libraries/Utilities/BackHandler.js.flow

@@ -0,0 +1,25 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ *
+ * @flow
+ * @format
+ */
+
+'use strict';
+
+export type BackPressEventName = 'backPress' | 'hardwareBackPress';
+
+type TBackHandler = {
+  exitApp(): void,
+  addEventListener(
+    eventName: BackPressEventName,
+    handler: () => ?boolean,
+  ): {remove: () => void, ...},
+};
+
+declare const BackHandler: TBackHandler;
+
+declare export default typeof BackHandler;