Allow NetworkStack to find the telephony service

The network stack needs access to TelephonyManager#getAllCellInfo to
send network conditions broadcasts.

Bug: 122843997
Test: Flashed, verified violation not shown and cell info obtained
properly.

Change-Id: I6ef2858c9a2d1fbbb993164a93bd985e0eee8887

private/network_stack.te

@@ -19,5 +19,6 @@ allow network_stack self:packet_socket create_socket_perms_no_ioctl;
 
 allow network_stack app_api_service:service_manager find;
 allow network_stack netd_service:service_manager find;
+allow network_stack radio_service:service_manager find;
 
 binder_call(network_stack, netd);