Update CHANGELOG

Author: mpkorstanje

CHANGELOG.md

@@ -7,6 +7,8 @@ This project adheres to [Semantic Versioning](http://semver.org).
 This document is formatted according to the principles of [Keep A CHANGELOG](http://keepachangelog.com).
 
 ## [Unreleased]
+### Fixed
+- [Java] Avoid unnecessary unboxing to Character
 
 ## [32.1.0] - 2025-04-04
 ### Changed