Allow tethering find netork stack service

Allow tethering service which is running in the same process as network
stack service "find" network stack service. Original design is passing
network_stack binder to tethering service directly when tethering
service is created. To allow creating tethering service and network
stack service in parallel. Let tethering service query network_stack
binder instead.

Bug: 144320246
Test: boot, flash, build
      OFF/ON hotspot

Change-Id: Ife0c2f4bdb2cfee4b5788d63d1cfc76af0ccc33c
diff --git a/private/network_stack.te b/private/network_stack.te
index a1d97b7..1295a07 100644
--- a/private/network_stack.te
+++ b/private/network_stack.te
@@ -35,3 +35,4 @@
 hal_client_domain(network_stack, hal_tetheroffload)
 # Create and share netlink_netfilter_sockets for tetheroffload.
 allow network_stack self:netlink_netfilter_socket create_socket_perms_no_ioctl;
+allow network_stack network_stack_service:service_manager find;