Add feature flag for local backups

ts/util/isLocalBackupsEnabled.dom.ts

@@ -1,26 +1,11 @@
 // Copyright 2025 Signal Messenger, LLC
 // SPDX-License-Identifier: AGPL-3.0-only
 
-import * as RemoteConfig from '../RemoteConfig.dom.js';
-import { isTestOrMockEnvironment } from '../environment.std.js';
-import { isStagingServer } from './isStagingServer.dom.js';
-import { isNightly } from './version.std.js';
+import { isFeaturedEnabledNoRedux } from './isFeatureEnabled.dom.js';
 
-export function isLocalBackupsEnabled(
-  reduxConfig?: RemoteConfig.ConfigMapType
-): boolean {
-  if (isStagingServer() || isTestOrMockEnvironment()) {
-    return true;
-  }
-
-  if (RemoteConfig.isEnabled('desktop.internalUser', reduxConfig)) {
-    return true;
-  }
-
-  const version = window.getVersion?.();
-  if (version != null) {
-    return isNightly(version);
-  }
-
-  return false;
+export function isLocalBackupsEnabled(): boolean {
+  return isFeaturedEnabledNoRedux({
+    betaKey: 'desktop.localBackups.beta',
+    prodKey: 'desktop.localBackups.prod',
+  });
 }