Synchronize should also upload locally created files

### Steps to reproduce
1. Tab ... menu next to a remote folder and select "Synchronize"
2. Wait for the download to finish
3. Locally on the Android device change a file or create a new file/folder in the directory that was just "synchronized"
4. Repeat step 1

### Expected behaviour
- As the name "Synchronize" suggests, the locally changed or newly added file should be uploaded to the remote folder.

### Actual behaviour
- Nothing get's uploaded

### Conclusion
- The feature "synchronize" does in fact not synchronize anything but only downloads the remote folder to make it available offline. It should be labeled "Make available offline"

### Environment data
Android version: 11

Device model: Galaxy tab S7

Stock or customized system: Stock

Nextcloud app version: 3.15.0

Nextcloud server version: 20