Call DataSettingsManager to determine dafault data roaming in PIM

This cl replaces a internal private method in PhoneInterfaceManager
with calling DataSettingsManager.isDefaultDataRoamingEnabled to
determine the default data roaming value when resetting telephony.

It removes the duplication logic and possible inconsistency.

Bug: 136008634
Test: FrameworksTelephonyTests
Test: Telephony factory reset
Flag: EXEMPT (minior refactor without logic change)
Change-Id: Ia1316794f2c915804e48f6b119ff907c1a1dd60e
1 file changed