Replace ImsManager#isWfcEnabledByPlatform(). Bug: 140542283 Test: m RunSettingsRoboTests -j ROBOTEST_FILTER=WifiCallingSettingsForSubTest Test: m RunSettingsRoboTests -j ROBOTEST_FILTER=WifiCallingSettingsTest Test: m RunSettingsRoboTests -j ROBOTEST_FILTER=WifiCallingPreferenceControllerTest Change-Id: I85907efb39aecdb3fb18cacf11ce4510b898edc4