add Tracking AF to Tella

according to https://tella-app.org/privacy tracking is enabled by default:

User are free to disable this automatic information collection

means it's opt-out, hence Tracking.

Tella also collects information about your mobile device and internet connection, including device manufacturer, hardware, device ID, screen size, language, locale, connection status, network time, mobile data type, wireless network MAC address, and internet protocol data.

Plus more. Capture of the privacy page here.