SimOperatorLocationChanger with Magisk/KernelSU.
This module will start a cron job to constantly update these properties using resetprop:
[gsm.sim.operator.numeric]: [23402][gsm.sim.operator.iso-country]: [gb][gsm.sim.operator.alpha]: [O2][gsm.operator.numeric]: [23402][gsm.operator.iso-country]: [gb][gsm.operator.alpha]: [O2]
Also on first reboot after installation, data of the following packages will be cleared:
com.google.android.gmscom.google.android.gsfcom.android.vending