Use normalize convenience constructors.

Author: Tom Finley

src/Microsoft.ML.Data/Commands/TrainCommand.cs

@@ -523,10 +523,7 @@ public static bool AddNormalizerIfNeeded(IHostEnvironment env, IChannel ch, ITra
                 }
                 ch.Info("Automatically adding a MinMax normalization transform, use 'norm=Warn' or 'norm=No' to turn this behavior off.");
                 IDataView ApplyNormalizer(IHostEnvironment innerEnv, IDataView input)
-                    => NormalizeTransform.Create(innerEnv, new NormalizeTransform.MinMaxArguments()
-                    {
-                        Column = new[] { new NormalizeTransform.AffineColumn { Source = featureColumn, Name = featureColumn } }
-                    }, input);
+                    => NormalizeTransform.CreateMinMaxNormalizer(innerEnv, input, featureColumn);
 
                 if (view is IDataLoader loader)
                     view = CompositeDataLoader.ApplyTransform(env, loader, tag: null, creationArgs: null, ApplyNormalizer);

src/Microsoft.ML.Data/Transforms/NormalizeTransform.cs

@@ -222,10 +222,7 @@ public static bool CreateIfNeeded(IHostEnvironment env, ref RoleMappedData data,
             var featInfo = data.Schema.Feature;
             env.AssertValue(featInfo); // Should be defined, if FEaturesAreNormalized returned a definite value.
 
-            var view = Create(env, new MinMaxArguments()
-            {
-                Column = new[] { new AffineColumn() { Name = featInfo.Name, Source = featInfo.Name } }
-            }, data.Data);
+            var view = CreateMinMaxNormalizer(env, data.Data, name: featInfo.Name);
             data = RoleMappedData.Create(view, data.Schema.GetColumnRoleNames());
             return true;
         }