DPE, plus button with map container does not work

[michalpelka]

Describe the bug We observed that some of our components cannot be used with the development build. Those components internally are reflecting AZStd::map.

Assets required I've build minimal code example for you:

#pragma once

#include <AzCore/Component/Component.h>
#include <AzCore/std/containers/unordered_map.h>
class MySampleComponent : public AZ::Component
{
public:
   AZ_COMPONENT(MySampleComponent, "{E36C4B2C-794B-46E3-8E8D-05A6C705E467}");
   MySampleComponent() = default;
   ~MySampleComponent() override = default;

   static void Reflect(AZ::ReflectContext* context);
   // AZ::Component overrides ...
   void Activate() override {};
   void Deactivate() override {};

private:
    AZStd::unordered_map<AZStd::string, AZStd::string> m_map;
};

#include "MySampleComponent.h"
#include <AzCore/Serialization/SerializeContext.h>
#include <AzCore/Serialization/EditContext.h>

void MySampleComponent::Reflect(AZ::ReflectContext* context)
{
    if (auto serializeContext = azrtti_cast<AZ::SerializeContext*>(context))
    {
        serializeContext->Class<MySampleComponent, AZ::Component>()
            ->Version(0)
            ->Field("m_map", &MySampleComponent::m_map);
        if (auto editContext = serializeContext->GetEditContext())
        {
            editContext->Class<MySampleComponent>("MySampleComponent", "MySampleComponent")
                ->ClassElement(AZ::Edit::ClassElements::EditorData, "")
                ->Attribute(AZ::Edit::Attributes::Category, "SAMPLE")
                ->Attribute(AZ::Edit::Attributes::AppearsInAddComponentMenu, AZ_CRC_CE("Game"))
                ->DataElement(AZ::Edit::UIHandlers::Default, &MySampleComponent::m_map, "m_map", "m_map");
        }
    }
}

Steps to reproduce Steps to reproduce the behavior:

1. Add cited code to the project's Gem (Cmake, create a descriptor)
2. Compile against development
3. Add component "MySampleComponent" to any entity
4. Click on the plus sign to populate the map with elements.
5. Nothing happens. Expected behavior A window with a key should appear.

Actual behavior Actutally nothing is happening

Screenshots/Video

Found in Branch Name of or link to the branch where the issue occurs.

Commit ID from o3de/o3de Repository f28481174e6a8aa8be857c82fa2e720cc3f10d1d

Desktop/Device (please complete the following information):

• Device: [PC]
• OS: [Linux]
• Version [22.04]
• CPU [ Intel I9 ]
• GPU [NVidia RTX 4080]
• Memory [64Gb]

Additional context It is present in ROS 2 Gem spawner component. It works in 2310.1 release.

[michalpelka]

I've tested, it is not working on Windows as well.

[alexmontAmazon]

fix in review here: https://github.com/o3de/o3de/pull/17292

[alexmontAmazon]

fixed in development branch.