Add sepolicy rules for Thread Network HAL

Bug: b/283905423
Test: Build and run the Thread Network stack in Cuttlefish.
Change-Id: I783022c66b80274069f8f3c292d84918f41f8221
diff --git a/private/system_server.te b/private/system_server.te
index d30f657..006caf7 100644
--- a/private/system_server.te
+++ b/private/system_server.te
@@ -333,6 +333,7 @@
 hal_client_domain(system_server, hal_sensors)
 hal_client_domain(system_server, hal_tetheroffload)
 hal_client_domain(system_server, hal_thermal)
+hal_client_domain(system_server, hal_threadnetwork)
 hal_client_domain(system_server, hal_tv_cec)
 hal_client_domain(system_server, hal_tv_hdmi_cec)
 hal_client_domain(system_server, hal_tv_hdmi_connection)