Equivalent of swift "Data" for Kotlin

Hi there,

I am working on an app for both IOS and Android. I would like to save the user profile image and make it accessible on both platforms. It seems I can save Image as “Data” for IOS, but unlike other data types like String, Double, Android does does not have a “Data” data type. What format can I save an image in mongoDB that can sync to both IOS and Android?