COMPMID-934: Return an error in Validate when we don't support asymmetric padding

Currently an assert gets fired in debug mode, and we just ignore the asymmetric padding in release mode.

Change-Id: Ia6278b5722f7e93f356a975ab3243e6bb07e44a8
Reviewed-on: https://eu-gerrit-1.euhpc.arm.com/120840
Reviewed-by: Michele DiGiorgio <michele.digiorgio@arm.com>
Tested-by: Jenkins <bsgcomp@arm.com>
Reviewed-by: Georgios Pinitas <georgios.pinitas@arm.com>
diff --git a/src/core/GLES_COMPUTE/kernels/GCPoolingLayerKernel.cpp b/src/core/GLES_COMPUTE/kernels/GCPoolingLayerKernel.cpp
index 64b94c0..c688cd4 100644
--- a/src/core/GLES_COMPUTE/kernels/GCPoolingLayerKernel.cpp
+++ b/src/core/GLES_COMPUTE/kernels/GCPoolingLayerKernel.cpp
@@ -60,6 +60,7 @@
     ARM_COMPUTE_RETURN_ERROR_ON_DATA_TYPE_CHANNEL_NOT_IN(input, 1, DataType::F16, DataType::F32);
     ARM_COMPUTE_RETURN_ERROR_ON_MSG((is_data_type_quantized_asymmetric(input->data_type()) && pool_info.pool_type() == PoolingType::L2),
                                     "Unsupported combination of parameters!");
+    ARM_COMPUTE_RETURN_ERROR_ON(!pool_info.pad_stride_info().padding_is_symmetric());
 
     const bool         is_global_pooling = pool_info.is_global_pooling();
     const unsigned int pool_size         = is_global_pooling ? input->tensor_shape().x() : pool_info.pool_size().width;