Add changelog entry for Remote Config (#11500)

* Set FID in realtime request

* Update request method naming

* Update test

* Fix tests

* Fix test

* Mention changes in changelog

* Update FirebaseRemoteConfig/CHANGELOG.md

Co-authored-by: Nick Cooke <[email protected]>

---------

Co-authored-by: Nick Cooke <[email protected]>

Author: qdpham13

FirebaseRemoteConfig/CHANGELOG.md

@@ -1,6 +1,8 @@
 # 10.12.0
 - [fixed] Fix issue of real-time listeners not being properly removed. (#11458)
 - [fixed] Fix real-time fetches not being able to fetch the latest template due to an in-progress fetch. (#11465)
+- [changed] Internal improvements to support Remote Config real-time updates. (#11485)
+
 # 10.7.0
 - [feature] Added support for real-time config updates. Use the new `addOnConfigUpdateListener` API to get
   real-time updates. Existing [`fetch`](https://firebase.google.com/docs/reference/swift/firebaseremoteconfig/api/reference/Classes/RemoteConfig#fetch)