init.rc: setup qtaguid group ownership of ctrl and stat files

This will help get rid of android_aid.h in the kernel.
The group of the proc entries will be used in place of the default
values picked up by the xt_qtaguid netfilter module
(AID_NET_BW_STATS, AID_NET_BW_ACCT).
This change has no effect until the matching kernel changes are submitted.

Change-Id: I3c177e7b5caf9c59300eba6bd4a976634b333674
diff --git a/rootdir/init.rc b/rootdir/init.rc
index a76602c..5205200 100644
--- a/rootdir/init.rc
+++ b/rootdir/init.rc
@@ -120,6 +120,12 @@
     write /dev/cpuctl/apps/bg_non_interactive/cpu.rt_runtime_us 700000
     write /dev/cpuctl/apps/bg_non_interactive/cpu.rt_period_us 1000000
 
+# qtaguid will limit access to specific data based on group memberships.
+#   net_bw_acct grants impersonation of socket owners.
+#   net_bw_stats grants access to other apps' detailed tagged-socket stats.
+    chown root net_bw_acct /proc/net/xt_qtaguid/ctrl
+    chown root net_bw_stats /proc/net/xt_qtaguid/stats
+
 # Allow everybody to read the xt_qtaguid resource tracking misc dev.
 # This is needed by any process that uses socket tagging.
     chmod 0644 /dev/xt_qtaguid