IVGCVSW-6469 Add MirrorPad FrontEnd and Ref Support

 * Added PaddingMode enum to PaddingDescriptor to enable Symmetric and
   Reflect padding.
 * Added Symmetric and Reflect Ref implementation.
 * Added Serializer & Deserializer support.
 * Added unit tests.

Signed-off-by: Matthew Sloyan <matthew.sloyan@arm.com>
Change-Id: I4bed907b31742b32ccefe5e8ca39a6f1e5bd9dee
diff --git a/src/armnnSerializer/Serializer.cpp b/src/armnnSerializer/Serializer.cpp
index 84a9d53..c087843 100644
--- a/src/armnnSerializer/Serializer.cpp
+++ b/src/armnnSerializer/Serializer.cpp
@@ -894,7 +894,8 @@
 
     auto flatBufferPadDesc = serializer::CreatePadDescriptor(m_flatBufferBuilder,
                                                              m_flatBufferBuilder.CreateVector(padList),
-                                                             padDescriptor.m_PadValue);
+                                                             padDescriptor.m_PadValue,
+                                                             GetFlatBufferPaddingMode(padDescriptor.m_PaddingMode));
 
     auto flatBufferPadLayer = serializer::CreatePadLayer(m_flatBufferBuilder,
                                                          flatBufferBaseLayer,