[VOL-4519] Add bbsimctl command to invalidate MDS count of an ONU

Change-Id: I8cdb6c0d5381b952a87e1d24d87cab81de0ddaf9
diff --git a/api/bbsim/bbsim.proto b/api/bbsim/bbsim.proto
index c84cd77..d5eeab7 100644
--- a/api/bbsim/bbsim.proto
+++ b/api/bbsim/bbsim.proto
@@ -339,4 +339,8 @@
     //Return all the UNIs for all the ONUs
     rpc GetUnis (Empty) returns (UNIs) {
     }
+
+    //Invalidate the MDS counter for the ONU
+    rpc InvalidateMds (ONURequest) returns (Response) {
+    }
 }