[Settings] Replace getSimCount() API

Change design of monitor change in Settings.Global.MOBILE_DATA and
Settings.Global.DATA_ROAMING in order to avoid from accessing
getSimCount().

Bug: 144251589
Test: make RunSettingsRoboTests -j ROBOTEST_FILTER=RoamingPreferenceControllerTest
make RunSettingsRoboTests -j ROBOTEST_FILTER=VideoCallingPreferenceControllerTest

Merged-In: I965a0c07c7c9ef5897b33809bae6a7921977db18
Change-Id: I8010f74c41826b081aa9f599d33a9519a1888215
2 files changed