Add 5G NSA to collapsed RAT types list

Currently, getAllCollapsedRatTypes is used to retrieve
all RAT types which will be recorded into NetworkStatsService.
However, there is a missing part that 5G NSA virtual RAT type
is not added into this list. This makes callers such as statsd
do not aware of 5G NSA RAT type and missed to collect data
usage of it.

Test: atest NetworkStatsSubscriptionsMonitorTest#test5g
Test: adb shell cmd stats pull-source 10082
Test: ./out/host/linux-x86/bin/statsd_testdrive 10082
Test: atest UidAtomTests#testMobileBytesTransfer \
      UidAtomTests#testMobileBytesTransferByFgBg \
      UidAtomTests#testDataUsageBytesTransfer
Bug: 163021464
Change-Id: I0faeda20f0506a48ac1131b234c5fc40d95dfbe0