Probably nobody has never done anything like that.
You didn't find anything because there is nothing to find and no option to change that in software, unless you rip out entire SW and have it reworked, reprogrammed to fit you.
Either live with it or find wires leading to UCH. When you find wires from front left and front right door, switch their places, but that too will be a pain. Getting them out of the connector you may destroy them, cutting and soldering is better, but, do you really want to go through all of that?
Is the cluster canbus decoded locally or are there discrete wires to the two symbols.
If it's 2 wires they could be swapped at the cluster?
You would need a wiring diagram whichever route you choose.
Surprising fault though because I would think there may be other bits of logic hanging on whether it's the drivers or passenger door that's opened so I wouldn't necessarily assume it's as simple as swapping the wires on the uch.
I wonder if it's been like that from new?