IVGCVSW-2882 Fix include order in armnn public headers

Change-Id: I111eab934824348f5e9c1d1384be5a24546dc19a
Signed-off-by: Matthew Bentham <matthew.bentham@arm.com>
diff --git a/include/armnn/INetwork.hpp b/include/armnn/INetwork.hpp
index a4dd0da..b61206f 100644
--- a/include/armnn/INetwork.hpp
+++ b/include/armnn/INetwork.hpp
@@ -4,12 +4,11 @@
 //
 #pragma once
 
-#include <armnn/NetworkFwd.hpp>
 #include <armnn/DescriptorsFwd.hpp>
-#include <armnn/TensorFwd.hpp>
-#include <armnn/Optional.hpp>
 #include <armnn/ILayerVisitor.hpp>
-
+#include <armnn/NetworkFwd.hpp>
+#include <armnn/Optional.hpp>
+#include <armnn/TensorFwd.hpp>
 #include <armnn/Types.hpp>
 
 #include <memory>