in order to load test our FCM connector, it's needed to replace the actual
FCM backend w/ some bogus code/mock written in any language.
I've started on this to be able to change the FCM URLs:
Now, besides just System properties, I think it would be handy to have this
on our docker image as a ENV as well, so it's easy to spin up testing
containers and use other container for the dummy load.
any thoughts ?