[ONNX] Fix bugs in unsqueeze and pooling ops (#1644)

* Unsqueeze Fix

* Pooling fix

src/ngraph/frontend/onnx_import/op/unsqueeze.cpp

@@ -37,7 +37,7 @@ namespace ngraph
 
                 ASSERT_VALID_ARGUMENT(node, !axes.empty()) << "'axes' attribute is mandatory.";
 
-                std::sort(std::begin(axes), std::end(axes), std::greater<int64_t>());
+                std::sort(std::begin(axes), std::end(axes), std::less<int64_t>());
 
                 AxisVector input_order{reshape::get_default_axis_vector(data_shape.size())};
 

src/ngraph/frontend/onnx_import/utils/convpool.hpp

@@ -104,8 +104,8 @@ namespace ngraph
                 auto paddings = convpool::get_pads(node);
 
                 // Convert padding from CoordinateDiff to Shape objects
-                const CoordinateDiff& padding_below{paddings.first};
-                const CoordinateDiff& padding_above{paddings.second};
+                const CoordinateDiff& padding_above{paddings.first};
+                const CoordinateDiff& padding_below{paddings.second};
                 Shape padding_below_shape{std::begin(padding_below), std::end(padding_below)};
                 Shape padding_above_shape{std::begin(padding_above), std::end(padding_above)};