Put dbus-daemon into session slice
Systemd puts user services into app.slice by default since https://github.com/systemd/systemd/commit/23dce98e89616092007005692a4574ab908db5a6
Systemd puts user services into app.slice by default since https://github.com/systemd/systemd/commit/23dce98e89616092007005692a4574ab908db5a6