Using Kotlin coroutines, you can work with AlerDialog and get result from it as if you're writing synchronous code

Coroutine Alert Dialog.kt

viewLifecycleOwner.lifecycleScope.launch {
    val items = arrayOf("Foo", "Bar", "Baz")             
    val currentCheckedIdx = 0
    val newCheckedItem = suspendCancellableCoroutine<String> { cont ->
        MaterialAlertDialogBuilder(requireContext())
            .setTitle(R.string.some_title)
            .setSingleChoiceItems(
                modesStrings,
                currentCheckedIdx
            ) { dialog, which: Int ->
                cont.resume(items[which])
                dialog.dismiss()
            }.setOnDismissListener {
                if (cont.isActive)
                    cont.resume(items[currentCheckedIdx]) /*or cancel the continuation and handle the related exception*/
            }.show()
    }
    // use newItem. e.g. persist it
}