Summary: The device id was not properly passed to the interface factory, rendering the Mpris and mousepad UI useless
Test Plan: Mpris and mousepad UI in app are now actually filled with content
Reviewers: #kde_connect, apol
Reviewed By: #kde_connect, apol
Subscribers: #kde_connect
Tags: #kde_connect
Differential Revision: https://phabricator.kde.org/D12505