Exposed render scale and shadow distance to be set by script.

com.unity.render-pipelines.lightweight/LWRP/Data/LightweightPipelineAsset.cs

         public float renderScale
         {
             get { return m_RenderScale; }
+            set { m_RenderScale = value; }
         }
 
         public bool supportsDynamicBatching
         public float shadowDistance
         {
             get { return m_ShadowDistance; }
+            set { m_ShadowDistance = value; }
         }
 
         public int cascadeCount