"On device" either does not read non-default "Data storage folder" or does not read it after date is migrated to it

### Steps to reproduce
0. Default Data storage folder is selected (/storage/emulated/0/Android/media/com.nextcloud.client)
1. Select a folder to Sync (Download) and wait until it is done.
2. Go to On device, and the sync folder is there.
3. Change Data storage folder: Settings > Data storage folder> Select the second option (/storage/extSDCard/Android/media/com.nextcloud.client)
4. Wait until migration is ready
5. Go to On device and "No files here" is shown (but they are in the new folder, if open externally)
6. Change Data storage folder to default one (Step 0). Wait until migration is ready. Sync folder is there.

### Expected behaviour
- sync folders should be shown On device, independently of the Data storage folder selected.

### Actual behaviour
- sync folders are only shown On device when default Data storage folder is selected.

### Environment data
Android version: 5.1.1
Device model: Galaxi Grand Pr.
Nextcloud app version: Nextcloud dev Android App