Fix for validator failing on empty files

Gems/Multiplayer/Code/Include/Multiplayer/INetworkPlayerSpawner.h

@@ -0,0 +1,18 @@
+/*
+* All or portions of this file Copyright (c) Amazon.com, Inc. or its affiliates or
+* its licensors.
+*
+* For complete copyright and license terms please see the LICENSE at the root of this
+* distribution (the "License"). All use of this software is governed by the License,
+* or, if provided, by the license below or the license accompanying this file. Do not
+* remove or modify any license notices. This file is distributed on an "AS IS" BASIS,
+* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+*
+*/
+
+#pragma once
+
+namespace Multiplayer
+{
+
+}

Gems/Multiplayer/Code/Source/MultiplayerSystemComponent.cpp

@@ -433,7 +433,7 @@ namespace Multiplayer
 
         if (m_onConnectFunctor)
         {
-            // Default OnConnect behaviour has been overridden, 
+            // Default OnConnect behaviour has been overridden
             m_onConnectFunctor(connection, datum);
         }
         else

Gems/Multiplayer/Code/multiplayer_files.cmake

@@ -15,6 +15,7 @@ set(FILES
     Include/Multiplayer/IMultiplayer.h
     Include/Multiplayer/IMultiplayerComponentInput.h
     Include/Multiplayer/INetworkEntityManager.h
+    Include/Multiplayer/INetworkPlayerSpawner.h
     Include/Multiplayer/INetworkTime.h
     Include/Multiplayer/IReplicationWindow.h
     Include/Multiplayer/MultiplayerComponent.h