NetworkStatsService - xt_qtaguid non-ebpf - account stacked interface stats

Test: atest bpf_module_test clatd_test libbpf_android_test libnetdbpf_test
  netd_integration_test netd_unit_test netdutils_test
Bug: 150738490
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Change-Id: I297fcad0a83bd8c32c0fa6c6a77d83b42cd8c428