IpConnectivityMetrics: no metrics upload in tests

Similarly to ApfTest, this patch changes ConnectivityServiceTest to use
a mock object instead of IpConnectivityLog so that running
ConnectivityServiceTest does not generate android.net.metrics events.

Bug: 30450301
Change-Id: Ibc0479f381f26e60baefbae15407c62aecbf6666
3 files changed