CreateMode.REPLACE not respected when missing permissions

This is somewhat related to #159 but expresses itself in a different manner.

Assume you have a function to create some file. However this function tries to create a file that already exists, and was created with scoped storage or manually by the user, even if the app has granted the permissions of that folder. Then CreateMode.REPLACE is not respected. The code below creates a file named "hello (1).txt".

This is a limitation of using the MediaStore API, but I still thing this should be docummented as a pitfall of CreateMode.REPLACE or MediaStoreCompat.

```kotlin
fun testAlreadyCreated(context : Context) {
val file = MediaStoreCompat.createDownload(
context = context,
file = FileDescription(
name = "hello",
"test",
mimeType = "text/plain"
),
mode = CreateMode.REPLACE
)?.toStorageFile(context)

println("file created with the name = ${file?.name}" )
file?.openOutputStream()?.writer()?.use { writer ->
writer.write("Hello World!")
writer.flush()
}
}
```