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