Report NSA NR As NR Cell Dwell Rate Metric

TelephonyManager reports NSA connection as LTE. Thus, cell dwell rate
metric will never report that the device is in a 5G state. Changing to
specify the network type as NR when NSA connection mode detected.

Bug: 154877022
Test: On device on live network
Cellular Radio Access Technology:
       oos 30s 811ms (1.3%)
       lte 25m 42s 352ms (64.3%)
       nr 13m 46s 268ms (34.4%)

Change-Id: Iacbc5800160cd2a4dd42f6a5520dacc6f47be9a5