IVGCVSW-3606 Support memory import for Reference backend

Signed-off-by: Ferran Balaguer <ferran.balaguer@arm.com>
Change-Id: I94bd191f88e0911ad4e4727610e81cd7afa95512
diff --git a/src/backends/backendsCommon/ITensorHandleFactory.hpp b/src/backends/backendsCommon/ITensorHandleFactory.hpp
index 9e61b5f..26f6c9b 100644
--- a/src/backends/backendsCommon/ITensorHandleFactory.hpp
+++ b/src/backends/backendsCommon/ITensorHandleFactory.hpp
@@ -30,7 +30,7 @@
     virtual std::unique_ptr<ITensorHandle> CreateTensorHandle(const TensorInfo& tensorInfo,
                                                               DataLayout dataLayout) const = 0;
 
-    virtual const FactoryId GetId() const = 0;
+    virtual const FactoryId& GetId() const = 0;
 
     virtual bool SupportsSubTensors() const = 0;