IOS file downloaded not able to be located on device

Hi there

Using a standard implementation to download files and save them locally on the device.
When they are downloaded, I am not able to locate them on the device with for example "File Explorer" app, tried on emulator and physical iPad.

```js
const urlExtensions = this.getUrlExtension(attachment.url);
const localFile = `${RNFS.LibraryDirectoryPath}/${attachment.title}.${urlExtensions}`;

const options = {
fromUrl: attachment.url,
toFile: localFile,
fileCache: true
};

if (await RNFS.exists(localFile)) {
FileViewer.open(localFile);
} else {
await RNFS.downloadFile(options).promise
.then(() => {
FileViewer.open(localFile);
})
.then((res) => {
// success
// console.log("success");
})
.catch(error => {
// error
console.log("Attachment open error: ", error);
});
}
```

Also tried to use "DocumentDirectoryPath", same issue.

Thanks in advance

Regards