feat(android/app): Network settings for Cloud downloads

Downloadmanager framework in android allows to change network settings for each download.
It should be possible for keyman users to change these settings, e.g "Allow download on metered connections" or "allow download on roaming connection".

**Solution:**
Add a network settings page to Keyman Settings

**Alternative:**
Download settings are controlled by android app settings.

**Product context**
- OS: Android