make roaming visual studio profile option persister handle bool? data type

src/VisualStudio/Core/Def/Implementation/Options/RoamingVisualStudioProfileOptionPersister.cs

@@ -174,6 +174,11 @@ public bool TryFetch(OptionKey optionKey, out object value)
                 value = longValue != 0;
                 return true;
             }
+            else if (optionKey.Option.Type == typeof(bool?))
+            {
+                // when nullable type is assigned to object, it can lose nullable type.
+                return (value is bool) || (value == null);
+            }
             else if (value != null && optionKey.Option.Type != value.GetType())
             {
                 // We got something back different than we expected, so fail to deserialize