Disallow access to proc_net for ephemeral_app

Test: Boots, runs
Bug: 32713782
Change-Id: Ia58db3c4c0159482f08e72ef638f3e1736095918
diff --git a/private/ephemeral_app.te b/private/ephemeral_app.te
index 2b94827..2b0515a 100644
--- a/private/ephemeral_app.te
+++ b/private/ephemeral_app.te
@@ -52,3 +52,7 @@
 # Directly access external storage
 neverallow ephemeral_app { sdcard_type media_rw_data_file }:file {open create};
 neverallow ephemeral_app { sdcard_type media_rw_data_file }:dir search;
+
+# Avoid reads to proc_net, it contains too much device wide information about
+# ongoing connections.
+neverallow ephemeral_app proc_net:file no_rw_file_perms;