It literally serves no purpose in the android port.

However, in a updated version of the game (which is lost), it was given a purpose to use it which was a insanity meter,

Basically, it would go up after an animatronic entered the room and you needed to go into the locker to "calm down" or you would die.

But then there is the question, why did the locker even exist before the addition of the insanity? I DON'T KNOW!