Add route for manual sync guide (#50693)

**Related issue:** #50001


<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->

## Summary by CodeRabbit

* **New Features**
* Added a redirect from the Android manual sync learn-more page to the
updated setup guide.

<!-- end of auto-generated comment: release notes by coderabbit.ai -->

website/config/routes.js

@@ -1381,7 +1381,7 @@ module.exports.routes = {
   'GET /learn-more-about/software-update-status': 'https://developers.google.com/android/management/reference/rest/v1/enterprises.devices#SystemUpdateInfo',
   'GET /learn-more-about/linux-disk-encryption': '/guides/enforce-disk-encryption#enforce-disk-encryption-on-linux',
   'GET /learn-more-about/removal-behavior': '/guides/custom-os-settings#removal-behavior',
-
+  'GET /learn-more-about/android-manual-sync': '/guides/how-to-manually-sync-an-android-device',
 
   // Sitemap
   // =============================================================================================================