Kotlin not writing to file

I have a file that I am trying to read information from and then update the file. I am able to read all the information from the file perfectly but when I go to write to the file, the file is not being written too.

Here is the code I am using to write to the file.

fun saveToFile(context: Context){
            try{
                Log.d("StatsAdapter", "Finding file.")
                val writer = OutputStreamWriter(context.openFileOutput("stats.txt", Context.MODE_PRIVATE))
                Log.d("StatsAdapter", "Writing.")
                writer.write("Hello")
                writer.flush()
                writer.close()
            } catch (e: IOException) {
                Log.d("StatsAdapter", "" + e)
            }
        }

The file stats.txt is an empty text file in assets on android studio, which gets read fine (I threw some basic information in to check reading). But when I go to write to the file, nothing appears in the file. Any ideas would be greatly appreciated :)