Fix NR display logic for non-LTE RATs

Get the data network type from NetworkRegistrationInfo instead of from
ServiceState. Also explicitly check for LTE or LTE_CA before setting
the NR override network type. This prevents the case where the network
type could be IWLAN and the override network type is NR.

Test: atest NetworkTypeControllerTest
Bug: 178111905
Change-Id: Ic22c60f19b6cd2c7fc4388f27f2ef1aaaba2e66d
Merged-In: Ic22c60f19b6cd2c7fc4388f27f2ef1aaaba2e66d
(cherry picked from commit 9570b78a)