Remove accessors for legacy int score from NAI

These are no longer useful. Also, NAI no longer needs to
be comparable, and it should no longer be – comparing 2
NAIs only make sense in the context of a specific request.

Bug: 238139913
Test: ConnectivityServiceTest IpConnectivityMetricsTest
Change-Id: I6967ad6f08380213c29f3d47d6422f8bbea1946c
5 files changed