Collect network metrics in BEP and JSON profiles.

BUG=b:311169573
TEST=https://ui.perfetto.dev/#!/?s=2a4e27004ea93d2723c2f5ec62ce56156af7be8916ec72faf1ae51718b5a4954
has network up/down lanes.

Change-Id: Ic0389181c26cb34383b070f72a172c23cdc79d19
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/bazel/+/5056606
Reviewed-by: Matt Stark <[email protected]>
Reviewed-by: Tim Bain <[email protected]>
Commit-Queue: Jingwen Chen <[email protected]>
Tested-by: Jingwen Chen <[email protected]>
Auto-Submit: Jingwen Chen <[email protected]>

Author: jin

bazelrcs/common.bazelrc

@@ -68,6 +68,10 @@ build --nostamp
 # Minimize remote cache downloads
 build --remote_download_toplevel
 
+# Collect system-wide network metrics in JSON profiles and BEP
+# (build_metrics.network_metrics)
+build --experimental_collect_system_network_usage
+
 ###
 # Correctness guarantees
 ###