Comment 17 for bug 1508081

Summarizing plan:

system-image-dbus adds a "force" (or some other name) method to the update which would set allowOverGsm to true

system-image-dbus should proxy the started signal from udm

system-settings will display "Download now" button if the started signal hasn't been received, which will call the force method on s-i-d to force the download regardless of network type.