it is not possible to pragmatically get the permission... but ill suggest you to put that line of code in try{} catch{} which make your app unfortunately stop... and in catch body make a dialog box which will navigate the user to small tutorial to enable the draw over other apps permission... then on yes button click put this code...
Intent callSettingIntent= new Intent(Settings.ACTION_MANAGE_OVERLAY_PERMISSION);
startActivity(callSettingIntent);
this intent is to directly open the list of draw over other apps to manage permissions and then from here it is one click to the draw over other apps Permissions ... i know this is Not the answer you're looking for... but Im doing this in my apps...