Uses 3GPP data from a disabled modem in location queries
GeoClue does not invalidate its 3GPP tower data when a modem supplying this data is disabled, but will keep submitting the old data forever (or until the modem is enabled again and receives new data) in MLS location queries.
There is a on_mm_modem_state_notify ()
function in gclue-modem-manager.c, but it's disconnected when the modem is found to be in enabled state and does not detect disabling.
The modem state notify callback should be kept connected all the time and the clear_3gpp_location ()
function called when the modem is disabled.