Can't use setOnSystemUiVisibilityChangeListener() function for jellybean android version. Any other equivalent??

On using setOnSystemUiVisibilityChangeListener() function as a call back to unity for pausing the game while notification status bar is made visible, it intakes the volume up/down button event too in Jellybean android devices, but works well with other versions. Tried using onWindowFocusChanged() funtion but it extends from activity which makes game crash on startup. We are making the setOnSystemUiVisibilityChangeListener() call for Unity from a jar. Can anyone tell how to go about solving this issue? Thanks for any suggestions.