Fix broken libbpf_test

The libbpf_test BpfNetworkStatsHelperTest.TestGetUidStatsTotal is
broken due to the change of StatsValue struct in libbpf. This patch
fix the test and cleaned up the warnings.

Test: ./libbpf_test
Bug: 30950746
Change-Id: I0ccfe52bc6db41325b061f8eeb041018da62f314
1 file changed