Update CHANGELOG.md

Author: AswinRajGopal

Packages/com.unity.inputsystem/CHANGELOG.md

@@ -22,6 +22,7 @@ however, it has to be formatted properly to pass verification tests.
 - Fixed Inspector Window being refreshed all the time when a PlayerInput component is present with Invoke Unity Events nofication mode chosen [ISXB-1448](https://issuetracker.unity3d.com/product/unity/issues/guid/ISXB-1448)
 - Fixed an issue where an action with a name containing a slash "/" could not be found via `InputActionAsset.FindAction(string,bool)`. [ISXB-1306](https://issuetracker.unity3d.com/product/unity/issues/guid/ISXB-1306).
 - Fixed Gamepad stick up/down inputs that were not recognized in WebGL. [ISXB-1090](https://issuetracker.unity3d.com/product/unity/issues/guid/ISXB-1090)
+- Fixed Action with custom processor serialises enums by index rather than by value. [ISXB-1474](https://issuetracker.unity3d.com/product/unity/issues/guid/ISXB-1474)
 
 ## [1.14.0] - 2025-03-20