I've made some tests and...
Go to *#*#0702#*#* -> Common settings. There is UPDATE_IMSCONFIG_BY_CARRIERCONFIG value with default value 1. After changing it to 0, it stays same after reboot.
So I copied two xml files to local directory and then changed values of:
It also stays after reboot.
- CONFIG_XML to local path /storage/emulated/0/imssetting/sim_configuration.xml
- UT_XML to local path /storage/emulated/0/imssetting/ut_default_setting.xml
But... nothing happens. SIM 2 Provisioned and SIM 2 Policy (testing it on my SIM2) settings are diffrent than these in xml files. It's weird that it correctly sets XCAP_APN_NAME to T-Mobile XCAP (my carrier is T-Mobile PL), but a few of settings are diffrent...
Additionaly, Setting VOWIFI_ENABLED_BY_PLATFORM to 1 in sim_configuration.xml doesn't sets it in ImsSetting app. Also, Provisioned and Policy setting always returns to default after reboot. Only Common settings are saved and surviving device reboot.
I think that it can somehow work, but we need find out how
I confirm your results. What did you change on ut_default_setting.xml ? I couldn't find any related option so I didn't change the path. I think we are really close, we just need to find the correct setting.