Added release note to update GTMSessionFetcher (#10780)

Author: maneesht

FirebaseStorage/CHANGELOG.md

@@ -1,5 +1,7 @@
 # 10.5.0
 - [added] Added Storage API to limit upload chunk size. (#10137)
+- [fixed] Run `pod update` or `File -> Packages -> Update to latest Packages` to update the `GTMSessionFetcher` dependency to at least version `3.1.0`.
+  This fixes an issue where it infinitely retries when FirebaseStorage returns a 500 response.
 
 # 10.3.0
 - [fixed] Use dedicated serial queue for Storage uploads and downloads instead of a (concurrent) global queue.