[Input System] The "Add Control Scheme..." popup now requires explicit Save/Close user action (case ISXB-1131)

o Previously clicking outside the popup window (anywhere in the editor) would close the popup window.

o This would leave a new blank (unnamed, orphaned) control scheme populating the UI - this was confusing.

o Now this popup will persist until the user explictly chooses to Save or Cancel.

Author: AlexTyrer

Packages/com.unity.inputsystem/InputSystem/Editor/UITKAssetEditor/Views/ControlSchemesView.cs

@@ -63,7 +63,6 @@ public ControlSchemesView(VisualElement root, StateContainer stateContainer, boo
             m_ModalWindow.Add(popupWindow);
             root.Add(m_ModalWindow);
             m_ModalWindow.StretchToParentSize();
-            m_ModalWindow.RegisterCallback<ClickEvent>(evt => CloseView());
             popupWindow.RegisterCallback<ClickEvent>(evt => evt.StopPropagation());
 
             m_ListView = controlSchemeVisualElement.Q<MultiColumnListView>(kControlSchemesListView);