sepolicy changes for network stack app

The networking stack app hosts services that used to be in the system
server (IpClient, NetworkMonitor for now), but in a different process to
be packaged as a mainline module.

Test: booted, verified networking stack working when in app
Change-Id: I300a556f51b35c17378af961cea1ec937444e597
diff --git a/private/compat/26.0/26.0.ignore.cil b/private/compat/26.0/26.0.ignore.cil
index 588c138..8ddefa1 100644
--- a/private/compat/26.0/26.0.ignore.cil
+++ b/private/compat/26.0/26.0.ignore.cil
@@ -121,6 +121,7 @@
     mnt_product_file
     mnt_vendor_file
     netd_stable_secret_prop
+    network_stack
     network_watchlist_data_file
     network_watchlist_service
     overlayfs_file