If the device does not have any telephony support (either via the
build-time config_show_sim_info=false boolean flag, or when not
declaring the PackageManager.FEATURE_TELEPHONY_DATA feature flag),
returning UNSUPPORTED_ON_DEVICE makes more sense than
CONDITIONALLY_UNAVAILABLE, as there is no runtime change that would
make it available.
This change also aligns the behavior with the deviceinfo/phonenumber
entry.
Bug: 395714454
Flag: EXEMPT bugfix
Test: atest MobileNetworkPhoneNumberPreferenceControllerTest
Change-Id: I5f2392969fad1884a89de3870ad37be5601fbe37
a66d27c488