IVGCVSW-5418 'ExecuteNetwork test for MobileBERT'

* Refactored the code for checking constant inputs.
* Added a unit test for ADD operator with constant input.

Signed-off-by: Sadik Armagan <sadik.armagan@arm.com>
Change-Id: Ie7207e5a1ce77ea305552859de32a66e07c68a6f
diff --git a/delegate/src/Quantization.hpp b/delegate/src/Quantization.hpp
index 565f1e3..3c274c6 100644
--- a/delegate/src/Quantization.hpp
+++ b/delegate/src/Quantization.hpp
@@ -73,6 +73,15 @@
     armnn::IOutputSlot& outputSlot = dequantizeLayer->GetOutputSlot(0);
     outputSlot.SetTensorInfo(outputTensorInfo);
 
+    auto inputsTensorsProcess = ProcessInputs(dequantizeLayer,
+                                              delegateData,
+                                              tfLiteContext,
+                                              tfLiteNode);
+    if (inputsTensorsProcess == kTfLiteError)
+    {
+        return inputsTensorsProcess;
+    }
+
     return Connect(dequantizeLayer, tfLiteNode, delegateData);
 }