LA-Managed: switch to experimental matrix product by default

src/Numerics/Providers/LinearAlgebra/ManagedLinearAlgebraProvider.cs

@@ -42,11 +42,11 @@ namespace MathNet.Numerics.Providers.LinearAlgebra
     /// </summary>
     public partial class ManagedLinearAlgebraProvider : ILinearAlgebraProvider
     {
-        private Variation _variation;
+        private readonly Variation _variation;
 
         public ManagedLinearAlgebraProvider()
         {
-            _variation = Variation.Original;
+            _variation = Variation.Experimental;
         }
 
         internal ManagedLinearAlgebraProvider(Variation variation)