Fix cubemap static preview + remove custom inspector

com.unity.render-pipelines.high-definition/CHANGELOG.md

@@ -101,6 +101,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 - Fixed an issue where entering playmode would close the LookDev window.
 - Fixed Cutoff not working properly with ray tracing shaders default and SG (case 1261292).
 - Fixed shader compilation issue with Hair shader and debug display mode
+- Fixed cubemap static preview not updated when the asset is imported.
 
 ### Changed
 - Preparation pass for RTSSShadows to be supported by render graph.

com.unity.render-pipelines.high-definition/Editor/Lighting/Reflection/HDReflectionProbeEditor.Preview.cs

@@ -5,7 +5,7 @@ namespace UnityEditor.Rendering.HighDefinition
 {
     sealed partial class HDReflectionProbeEditor
     {
-        HDCubemapInspector m_CubemapEditor;
+        Editor m_CubemapEditor;
 
         public override bool HasPreviewGUI()
         {
@@ -22,8 +22,7 @@ public override bool HasPreviewGUI()
             if (ValidPreviewSetup() && m_CubemapEditor == null)
             {
                 Editor editor = m_CubemapEditor;
-                CreateCachedEditor(GetTexture(this, target), typeof(HDCubemapInspector), ref editor);
-                m_CubemapEditor = editor as HDCubemapInspector;
+                m_CubemapEditor = CreateEditor(GetTexture(this, target));
             }
 
             // If having one probe selected we always want preview (to prevent preview window from popping)