[Input System] Added CHANGELOG.md entry for ISubmitHandler.OnSubmit fix (ISXB-1141)

Author: AlexTyrer

Packages/com.unity.inputsystem/CHANGELOG.md

@@ -15,6 +15,7 @@ however, it has to be formatted properly to pass verification tests.
 - Reverted changes from 0ddd534d8 (ISXB-746) which introduced a regression [ISXB-1127](https://issuetracker.unity3d.com/product/unity/issues/guid/ISXB-1127).
 - Fixed `ArgumentNullException: Value cannot be null.` during the migration of Project-wide Input Actions from `InputManager.asset` to `InputSystem_Actions.inputactions` asset which lead do the lost of the configuration [ISXB-1105](https://issuetracker.unity3d.com/product/unity/issues/guid/ISXB-1105)
 - Fixed pointerId staying the same when simultaneously releasing and then pressing in the same frame on mobile using touch. [ISXB-1006](https://issuetracker.unity3d.com/product/unity/issues/guid/ISXB-845)
+- Fixed ISubmitHandler.OnSubmit event processing when operating in Manual Update mode (ISXB-1141)
 
 ### Changed
 - Added back the InputManager to InputSystem project-wide asset migration code with performance improvement (ISX-2086)