Fix permissions for bluetooth tethering.

Allow bluetooth to find the NetworkStack service so tethering can be
started.

Test: booted, BT tethering obtains IP address and denials not shown
Bug: b/112869080
Change-Id: I726d818f4f9a9adcd98c834726ed22376076ac7b
diff --git a/private/bluetooth.te b/private/bluetooth.te
index 68cfb35..fcbd509 100644
--- a/private/bluetooth.te
+++ b/private/bluetooth.te
@@ -52,6 +52,7 @@
 allow bluetooth radio_service:service_manager find;
 allow bluetooth app_api_service:service_manager find;
 allow bluetooth system_api_service:service_manager find;
+allow bluetooth network_stack_service:service_manager find;
 
 # already open bugreport file descriptors may be shared with
 # the bluetooth process, from a file in