SEPolicy updates for adding native flag namespace(netd).

For experiment flag testing, we add a flag netd and have
SEPolicy updates.

Test:  add sepolicy, m -j, check GetServerConfigurableFlag function in netd
Bug:122050512
Change-Id: I21c844c277afc358085d80447f16e4c0d4eba5b3
diff --git a/private/property_contexts b/private/property_contexts
index 06c2822..8d87262 100644
--- a/private/property_contexts
+++ b/private/property_contexts
@@ -170,6 +170,7 @@
 device_config.reset_performed           u:object_r:device_config_reset_performed_prop:s0
 persist.device_config.attempted_boot_count        u:object_r:device_config_boot_count_prop:s0
 persist.device_config.global_settings.native_flags_health_check_enabled u:object_r:device_config_flags_health_check_prop:s0
+persist.device_config.netd_native.           u:object_r:device_config_netd_native_prop:s0
 
 apexd.                  u:object_r:apexd_prop:s0
 persist.apexd.          u:object_r:apexd_prop:s0