[Fix]Move all LW resources into the resources asset.

ScriptableRenderPipeline/LightweightPipeline/LWRP/Data/LightweightPipelineAsset.cs

 #if UNITY_EDITOR
+using System;
 using UnityEditor;
 using UnityEditor.ProjectWindowCallback;
 #endif
         [SerializeField] private ShadowCascades m_ShadowCascades = ShadowCascades.FOUR_CASCADES;
         [SerializeField] private float m_Cascade2Split = 0.25f;
         [SerializeField] private Vector3 m_Cascade4Split = new Vector3(0.067f, 0.2f, 0.467f);
-
-        // Resources
-        [SerializeField] private Shader m_BlitShader;
-        [SerializeField] private Shader m_CopyDepthShader;
+        
+        [SerializeField]
+        private LightweightPipelineResource m_ResourceAsset;
-        private LightweightPipelineResource m_ResourceAsset;
-
         [MenuItem("Assets/Create/Render Pipeline/Lightweight/Pipeline Asset", priority = CoreUtils.assetCreateMenuPriority1)]
         static void CreateLightweightPipeline()
         {
             public override void Action(int instanceId, string pathName, string resourceFile)
             {
                 var instance = CreateInstance<LightweightPipelineAsset>();
-                instance.m_BlitShader = Shader.Find(LightweightShaderUtils.GetShaderPath(ShaderPathID.HIDDEN_BLIT));
-                instance.m_CopyDepthShader = Shader.Find(LightweightShaderUtils.GetShaderPath(ShaderPathID.HIDDEN_DEPTH_COPY));
-
+                instance.LoadResourceFile();
                 AssetDatabase.CreateAsset(instance, pathName);
             }
         }
 
         public Shader BlitShader
         {
-            get { return m_BlitShader; }
+            get
+            {
+#if UNITY_EDITOR
+                if (m_ResourceAsset == null)
+                    LoadResourceFile();
+#endif
+                if (m_ResourceAsset)
+                    return m_ResourceAsset.BlitShader;
+                return null;
+            }
-            get { return m_CopyDepthShader; }
+            get
+            {
+#if UNITY_EDITOR
+                if (m_ResourceAsset == null)
+                    LoadResourceFile();
+#endif
+                if (m_ResourceAsset)
+                    return m_ResourceAsset.CopyDepthShader;
+                return null;
+            }
         }
     }
 }

ScriptableRenderPipeline/LightweightPipeline/LWRP/Data/LightweightPipelineResource.asset

     type: 2}
   DefaultTerrainMaterial: {fileID: 2100000, guid: 594ea882c5a793440b60ff72d896021e,
     type: 2}
+  BlitShader: {fileID: 4800000, guid: c17132b1f77d20942aa75f8429c0f8bc, type: 3}
+  CopyDepthShader: {fileID: 4800000, guid: d6dae50ee9e1bfa4db75f19f99355220, type: 3}

ScriptableRenderPipeline/LightweightPipeline/LWRP/Data/LightweightPipelineResource.cs

 
 public class LightweightPipelineResource : ScriptableObject
 {
+    public Shader BlitShader;
+    public Shader CopyDepthShader;
+#if UNITY_EDITOR
+#endif
 }