Added unit tests for ImeiInfoPreferenceController visibility

The new test checks whether the item is available when
config_show_sim_info=false, when telephony is not data capable and
when the user is not admin,

The default visibility status for all tests is defined in the test
setup().

Bug: 395714454
Flag: EXEMPT test only
Test: atest ImeiInfoPreferenceControllerTest
Change-Id: Ic4df12da216e5c343cf696d931ff02dc942d105f