Using subscriptionInfo to get the network name.
Bug: 203035698
Bug: 201591202
Test: make RunSettingsRoboTests
ROBOTEST_FILTER=RenameMobileNetworkDialogFragmentTest (PASS)
Change-Id: I84848a2801172b46f7cc3ff39d88ad57e34514a4
(cherry picked from commit 050b6d5224
)