APK size increase after baking lighting

Hi there. I have created a scene for a mobile game and after baking the lighting and the APK size more than doubled. The lighting maps themselves were fairly small, it was the lit shader which had balooned in size. Is there any way I can stop this from happening as I am making a mobile game so want to keep it slim. I don't need much but would like to add a bit of detail from the lighting if possible but the size increase makes it not worth it at the moment. many thanks.