[Settings] Code refactor

Minor code refactor

Bug: 141833767
Test: make RunSettingsRoboTests -j ROBOTEST_FILTER=DataUsagePreferenceControllerTest
Merged-In: I060e7c880d91a0e5059610c5ceae319d47c19c7a
Change-Id: I378b3c7ad5531efd5f2dad4bdafbcddacaf66db4
1 file changed