Revert "Introducing vm_tethering_service as system_server_service"

This reverts commit 70e6e885ae51673a7873835ca2f69a56586e088c.

Reason for revert:  <Potential culprit for b/347203579  - verifying through ABTD before revert submission. This is part of the standard investigation process, and does not mean your CL will be reverted.>

Change-Id: I28064a2f38114d4e91356828576bfb3b9030b977
diff --git a/private/service.te b/private/service.te
index 6c55ed4..1fb4d1d 100644
--- a/private/service.te
+++ b/private/service.te
@@ -31,8 +31,7 @@
     type virtualization_maintenance_service, service_manager_type;
 ')
 is_flag_enabled(RELEASE_AVF_ENABLE_NETWORK, `
-    type vm_tethering_service, system_server_service, service_manager_type;
-    type vmnic_service,        service_manager_type;
+    type vmnic_service, service_manager_type;
 ')
 
 type uce_service,                   service_manager_type;