Fix warnings

com.unity.render-pipelines.core/CoreRP/Tool/Gizmo6FacesBox.cs

         {
             get
             {
-                return m_faceColorsSelected ?? (m_faceColorsSelected = new Color[]
-                {
-                    new Color(1f, 0f, 0f, .15f),
-                    new Color(0f, 1f, 0f, .15f),
-                    new Color(0f, 0f, 1f, .15f),
-                    new Color(1f, 0f, 0f, .15f),
-                    new Color(0f, 1f, 0f, .15f),
-                    new Color(0f, 0f, 1f, .15f)
-                });
                 return m_faceColorsSelected ?? (m_faceColorsSelected = monochromeSelectedFace
                     ? new Color[]
                     {

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

 using UnityEngine;
 using UnityEngine.Experimental.Rendering;
 using UnityEngine.Experimental.Rendering.HDPipeline;
-using UnityEngine.Rendering;
-using UnityEngine.Experimental.Rendering;
 
 namespace UnityEditor.Experimental.Rendering
 {

com.unity.render-pipelines.high-definition/HDRP/Editor/Lighting/Reflection/HDReflectionProbeUI.cs

 using UnityEngine.Experimental.Rendering;
 using UnityEngine.Experimental.Rendering.HDPipeline;
 using UnityEngine.Rendering;
-using UnityEngine.Experimental.Rendering;
 
 namespace UnityEditor.Experimental.Rendering
 {

com.unity.render-pipelines.high-definition/HDRP/Editor/Lighting/Reflection/PlanarReflectionProbeUI.Drawers.cs

                 CED.Action(Drawer_SectionInfluenceSettings)
                 );
 
-        public static readonly CED.IDrawer SectionFoldoutProxySettings;
         public static readonly CED.IDrawer SectionFoldoutCaptureSettings;
 
         public static readonly CED.IDrawer SectionCaptureMirrorSettings = CED.Action(Drawer_SectionCaptureMirror);