Correctly shows HeightMap in LayeredLit shader UI when using height based blend without any displacement.

ScriptableRenderPipeline/HDRenderPipeline/HDRP/Editor/Material/LayeredLit/LayeredLitUI.cs

         MaterialProperty[] showLayer = new MaterialProperty[kMaxLayerCount];
         const string kShowLayer = "_ShowLayer";
 
+        bool m_UseHeightBasedBlend;
+
         protected override void FindMaterialProperties(MaterialProperty[] props)
         {
             base.FindMaterialLayerProperties(props);
                 EditorGUILayout.Space();
             }
 
-            DoLayerGUI(material, layerIndex, true);
+            DoLayerGUI(material, layerIndex, true, m_UseHeightBasedBlend);
 
             if (layerIndex == 0)
                 EditorGUILayout.Space();
 
             EditorGUI.BeginChangeCheck();
             EditorGUI.showMixedValue = useHeightBasedBlend.hasMixedValue;
-            bool enabled = EditorGUILayout.Toggle(styles.useHeightBasedBlendText, useHeightBasedBlend.floatValue > 0.0f);
+            m_UseHeightBasedBlend = EditorGUILayout.Toggle(styles.useHeightBasedBlendText, useHeightBasedBlend.floatValue > 0.0f);
-                useHeightBasedBlend.floatValue = enabled ? 1.0f : 0.0f;
+                useHeightBasedBlend.floatValue = m_UseHeightBasedBlend ? 1.0f : 0.0f;
-            if (enabled)
+            if (m_UseHeightBasedBlend)
             {
                 EditorGUI.indentLevel++;
                 m_MaterialEditor.ShaderProperty(heightTransition, styles.heightTransition);

ScriptableRenderPipeline/HDRenderPipeline/HDRP/Editor/Material/Lit/LitUI.cs

             }
         }
 
-        protected void DoLayerGUI(Material material, int layerIndex, bool isLayeredLit)
+        protected void DoLayerGUI(Material material, int layerIndex, bool isLayeredLit, bool showHeightMap)
         {
             EditorGUILayout.LabelField(Styles.InputsText, EditorStyles.boldLabel);
 
             }
 
             DisplacementMode displaceMode = (DisplacementMode)displacementMode.floatValue;
-            if(displaceMode != DisplacementMode.None)
+            if(displaceMode != DisplacementMode.None || showHeightMap)
             {
                 EditorGUI.BeginChangeCheck();
                 m_MaterialEditor.TexturePropertySingleLine(Styles.heightMapText, heightMap[layerIndex]);
 
         protected override void MaterialPropertiesGUI(Material material)
         {
-            DoLayerGUI(material, 0, false);
+            DoLayerGUI(material, 0, false, false);
             DoEmissiveGUI(material);
             // The parent Base.ShaderPropertiesGUI will call DoEmissionArea
         }