Limit route priority to 0-9 (#2911)

Limit route priority to 0-9

edge-hub/src/Microsoft.Azure.Devices.Edge.Hub.Core/config/RouteConfiguration.cs

@@ -1,6 +1,7 @@
 // Copyright (c) Microsoft. All rights reserved.
 namespace Microsoft.Azure.Devices.Edge.Hub.Core.Config
 {
+    using System;
     using System.ComponentModel;
     using Microsoft.Azure.Devices.Edge.Util;
     using Microsoft.Azure.Devices.Routing.Core;
@@ -22,8 +23,15 @@ public RouteConfiguration(string route)
         public RouteConfiguration(string route, uint priority, uint timeToLiveSecs)
         {
             this.Route = Preconditions.CheckNonWhiteSpace(route, nameof(route));
-            this.Priority = priority;
             this.TimeToLiveSecs = timeToLiveSecs;
+
+            // Verify the route, this must be either between [0-9], or the default value
+            if ((priority < 0 || priority > 9) && priority != RouteFactory.DefaultPriority)
+            {
+                throw new ArgumentOutOfRangeException(nameof(priority), priority, $"Invalid priority for route: {route}, priority can only be between 0-9");
+            }
+
+            this.Priority = priority;
         }
 
         [JsonProperty(PropertyName = "route")]