SEBA-664 Allow ONU to be manually disabled

Change-Id: Ib23d16eca9a0a9b6c4315791e285f6e52e858e8a
diff --git a/xos/synchronizer/models/volt.xproto b/xos/synchronizer/models/volt.xproto
index 8856c0f..25fbaf1 100644
--- a/xos/synchronizer/models/volt.xproto
+++ b/xos/synchronizer/models/volt.xproto
@@ -183,7 +183,7 @@
         max_length = 256];
     optional string admin_state = 6 [
         help_text = "admin state, whether port should be enabled",
-        choices = "(('DISABLED', 'DISABLED'), ('ENABLED', 'ENABLED'))",
+        choices = "(('DISABLED', 'DISABLED'), ('ENABLED', 'ENABLED'), ('ADMIN_DISABLED', 'ADMIN_DISABLED'))",
         default = "ENABLED",
         max_length = 32];
     optional string oper_status = 7 [