Prevent auto uploads on metered Wi-Fi

### Steps to reproduce
1. Connect to a metered WiFi network
2. Set up auto uploads
3. Take some pictures to trigger auto upload

### Expected behaviour

Uploads should be deferred until a non-metered network connection is available.

### Actual behaviour

Uploads use up the metered network's data volume.

### Can you reproduce this problem on https://try.nextcloud.com?

Server side does not matter.

### Environment data
Android version: 9

Device model: Poco F1

Stock or customized system: Stock

Nextcloud app version: Latest

Nextcloud server version: 19.0.2

Reverse proxy: nginx