Improve clarity of video and camera auto upload configuration

### Actual behaviour
The app only uploads photos, i.e. jpg files from my 'Auto upload' folders.
### Expected behaviour
The app should upload at least video, i.e. mp4, files as well.

### Steps to reproduce
1. Set Auto Upload Folder
2. Take a video
3. Check Nextcloud server => it isn't there

### Environment data
Android version:
Android 8.0.0

Device model:
Samsung Galaxy S7

Stock or customized system:
Stock software for AT&T version (G930A)

Nextcloud app version:
Latest, i.e #.3.0

Nextcloud server version:
14.0.1

### Logs
#### Web server error log
```not a server issue

Insert your webserver log here
```not a server issue

#### Nextcloud log (data/nextcloud.log)
```not a server issue

Insert your Nextcloud log here
```not a server issue

**NOTE:** Be super sure to remove sensitive data like passwords, note that everybody can look here! You can use the Issue Template application to prefill some of the required information: https://apps.nextcloud.com/apps/issuetemplate