Sample network statistics for sanity check.

After detailed poll events, sample high-level network statistics to
sanity check iface totals against UID totals.

Bug: 5248382
Change-Id: I1c1fbb7c094c9ff0c9dde416467c563dda68f478
diff --git a/services/java/com/android/server/EventLogTags.logtags b/services/java/com/android/server/EventLogTags.logtags
index 5429c0c..f0b5958 100644
--- a/services/java/com/android/server/EventLogTags.logtags
+++ b/services/java/com/android/server/EventLogTags.logtags
@@ -137,3 +137,10 @@
 # [ 8- 3] Detailed state ordinal (as defined by NetworkInfo.DetailedState)
 # [ 2- 0] Network type (as defined by ConnectivityManager)
 50020 connectivity_state_changed (custom|1|5)
+
+
+# ---------------------------
+# NetworkStatsService.java
+# ---------------------------
+51100 netstats_mobile_sample (iface_rx|2|2),(iface_tx|2|2),(uid_rx|2|2),(uid_tx|2|2)
+51101 netstats_wifi_sample (iface_rx|2|2),(iface_tx|2|2),(uid_rx|2|2),(uid_tx|2|2)