Move IsDirect = true into DirectPropertyBase

Author: heku

src/Avalonia.Base/DirectProperty.cs

@@ -32,7 +32,6 @@ internal DirectProperty(
         {
             Getter = getter ?? throw new ArgumentNullException(nameof(getter));
             Setter = setter;
-            IsDirect = true;
             IsReadOnly = setter is null;
         }
 
@@ -52,7 +51,6 @@ private DirectProperty(
         {
             Getter = getter ?? throw new ArgumentNullException(nameof(getter));
             Setter = setter;
-            IsDirect = true;
             IsReadOnly = setter is null;
         }
 

src/Avalonia.Base/DirectPropertyBase.cs

@@ -27,6 +27,7 @@ private protected DirectPropertyBase(
             AvaloniaPropertyMetadata metadata)
             : base(name, ownerType, ownerType, metadata)
         {
+            IsDirect = true;
             Owner = ownerType;
         }
 
@@ -42,6 +43,7 @@ private protected DirectPropertyBase(
             AvaloniaPropertyMetadata metadata)
             : base(source, ownerType, metadata)
         {
+            IsDirect = true;
             Owner = ownerType;
         }