Skip Cronet tests that call GetTaggedBytes() on P+ devices.

In Android P, /proc/net/xt_qtaguid/stats is no longer guaranteed to be
present, and has been replaced with eBPF Traffic Monitoring in netd. See:
https://source.android.com/devices/tech/datausage/ebpf-traffic-monitor

To read traffic statistics from netd, apps should use the API
NetworkStatsManager.queryDetailsForUidTag(). But this API does not provide
statistics for local traffic, only mobile and WiFi traffic, so it would not
work in tests that spin up a local server. So for now, GetTaggedBytes is
only supported on Android releases older than P.

Change-Id: Ida2b47624e1ac379799d00a21b8b41915579aece
Reviewed-on: https://chromium-review.googlesource.com/c/1470522
Commit-Queue: Paul Jensen <pauljensen@chromium.org>
Auto-Submit: Paul Jensen <pauljensen@chromium.org>
Reviewed-by: Peter Collingbourne <pcc@chromium.org>
Cr-Commit-Position: refs/heads/master@{#631850}
5 files changed