Show full screen bottom sheet

CustomBottomSheet.kt

override fun onCreateDialog(savedInstanceState: Bundle?): Dialog {
        val dialog = super.onCreateDialog(savedInstanceState)
        dialog.setOnShowListener { dialogInterface ->
            dialog.window?.findViewById<View>(R.id.design_bottom_sheet)?.let { bottomSheetView ->
                bottomSheetView.background = null
                /* bottomSheetView.let {
                     BottomSheetBehavior.from(it).isFitToContents = true
                     BottomSheetBehavior.from(it).state = BottomSheetBehavior.STATE_EXPANDED
                 }*/
                val bottomSheetDialog = dialogInterface as BottomSheetDialog
                setupFullHeight(bottomSheetDialog)
            }
        }
        return dialog
    }
    private fun setupFullHeight(bottomSheetDialog: BottomSheetDialog) {
        val bottomSheet: FrameLayout? = bottomSheetDialog.findViewById<View>(R.id.design_bottom_sheet) as FrameLayout?
        val behavior: BottomSheetBehavior<*> = BottomSheetBehavior.from(bottomSheet!!)
        val layoutParams: ViewGroup.LayoutParams = bottomSheet.layoutParams
        val windowHeight = Resources.getSystem().displayMetrics.heightPixels
        layoutParams.height = windowHeight
        behavior.peekHeight = windowHeight
        bottomSheet.layoutParams = layoutParams
        behavior.state = BottomSheetBehavior.STATE_EXPANDED
    }