So many posts, so many knowledge.
But all "half-knowledge"!

I have to admit I do not know exactly the working of location-test-gui, so I did not post. But for sure is it has different methods and we need the last one. AGNSS (AGPS).
This will give the receiver the desired satellite info like position of current location where are those satellites and their sky posititon (almanach, who says this is not stored on cell phone?).
We may also use the ACWP method, but this will give only ground location based on cell tower info (and/or SIM info, MCC).

For real testing you will need to reset the receiver cache by rebooting. No other chance to reset the GPS chip (afaik).
BUT, this is not enough. Before rebooting you need to reset the stored (not cached) last known position and timestamp.
This is the crudest way, but you will also see the GPS usage disclaimer again?

Happy testing...
And let us know that it will work for you!

For me none of nokia/google/vodafone worked.

P.S.: you may start to try with AGNSS.
I stop after 30/60 sec, that is definitely enough time for AGPS.

If you wanna try the cell tower/provider solution (ACWP), you may see that this method will just fetch the SIM/provider country code and position you in the middle of your currently located country (try it with DISabled SIM and you will see!). If it would fetch supl data it would locate you approximately 150m-1500m off your real position.

Again, happy testing...