IVGCVSW-3370 Add broadcasting support to PReLU to properly run the Android VTS/NN
tests

 * Updated ConvertPrelu to support input broadcasting
 * Updated the BroadcastTensor utility function so that it preserves
   the order of the inputs
 * Updated the documentation

Signed-off-by: Matteo Martincigh <matteo.martincigh@arm.com>
Change-Id: Ibbac6f7161132740e61c85f597f8be70cd5d7325
diff --git a/1.2/HalPolicy.cpp b/1.2/HalPolicy.cpp
index 1c6159e..e058e02 100644
--- a/1.2/HalPolicy.cpp
+++ b/1.2/HalPolicy.cpp
@@ -443,7 +443,7 @@
 
     if (!output)
     {
-        return Fail("%s: Could not read output 0", __func__);
+        return Fail("%s: Could not read output", __func__);
     }
 
     const armnn::TensorInfo& inputInfo  = input.GetTensorInfo();
@@ -467,8 +467,7 @@
         return Fail("%s: AddPreluLayer failed", __func__);
     }
 
-    input.Connect(layer->GetInputSlot(0));
-    alpha.Connect(layer->GetInputSlot(1));
+    BroadcastTensor(input, alpha, layer, *data.m_Network);
 
     return SetupAndTrackLayerOutputSlot<hal_1_2::HalPolicy>(operation, 0, *layer, model, data);
 }