In CyanogenMod 13, I've removed all telecom/telephony/GPS support from a ROM in an effort to reduce the device to basically be a wifi-only mini tablet. This entailed removing all relevant apps and a few libraries.
The ROM boots fine after removal, but lockscreen, security, and privacy aren't accessible in the settings; settings crashes when attempts are made to access any of them.
On previous versions of CyanogenMod on the same and another device this didn't happen, but then again I've updated the script I use to be more comprehensive as I discover new parts of the system that address telephony.
I've cross referenced the options in each settings subsection with the apps and libraries removed, and there seems to be zero crossover. Nothing in privacy, lockscreen, or security references GPS or telephony in any way.
I've done some tests to replace removed apps to try and do a process of elimination, but there are a lot of apps the script I use removes. I've only gotten through two or three of them so far, but none of them restored access. The obvious one seemed like it would be dialer.apk, but allowing that one did nothing.
- what telephony/GPS apps are required to run the aforementioned settings
- what the reasoning is behind this counter-intuitive entanglement, and
- how to maybe rebuild the ROM so that these apps and libs aren't required to access the full settings?