forwarder_guest_launcher can execute forwarder_guest

Bug: 340126051
Test: Prepare server running in the port number 12345 in the guest, and
run `forwarder_guest_launcher --host 192.168.0.1`.

Change-Id: If4f5523a285382341615b669eed0492f493b7577
diff --git a/libs/debian_service/proto/DebianService.proto b/libs/debian_service/proto/DebianService.proto
index 5e3286a..a887bf2 100644
--- a/libs/debian_service/proto/DebianService.proto
+++ b/libs/debian_service/proto/DebianService.proto
@@ -23,10 +23,12 @@
 
 service DebianService {
   rpc ReportVmIpAddr (IpAddr) returns (ReportVmIpAddrResponse) {}
-  rpc OpenForwardingRequestQueue (Empty) returns (stream ForwardingRequestItem) {}
+  rpc OpenForwardingRequestQueue (QueueOpeningRequest) returns (stream ForwardingRequestItem) {}
 }
 
-message Empty {}
+message QueueOpeningRequest {
+  int32 cid = 1;
+}
 
 message IpAddr {
   string addr = 1;