IVGCVSW-4077 Disable NEON memory import

* Temporarily handles cases in CalculateEdgeStrategy
  where dstFactory pointer is null when import is
  disabled.
* This patch is required for ensuring debug layer
  works correctly when executing a model on Neon.

Signed-off-by: James Conroy <james.conroy@arm.com>
Change-Id: I7304723246d362d6d9073c3d0b1224e194a8532c
diff --git a/src/backends/neon/NeonTensorHandleFactory.cpp b/src/backends/neon/NeonTensorHandleFactory.cpp
index 80f46d2..d5fef4e 100644
--- a/src/backends/neon/NeonTensorHandleFactory.cpp
+++ b/src/backends/neon/NeonTensorHandleFactory.cpp
@@ -104,7 +104,7 @@
 
 MemorySourceFlags NeonTensorHandleFactory::GetImportFlags() const
 {
-    return static_cast<MemorySourceFlags>(MemorySource::Malloc);
+    return 0;
 }
 
 } // namespace armnn