change default extend chrome hint

src/Avalonia.Controls/ApiCompatBaseline.txt

@@ -1,6 +1,7 @@
 Compat issues with assembly Avalonia.Controls:
 MembersMustExist : Member 'public void Avalonia.Controls.Embedding.Offscreen.OffscreenTopLevelImplBase.SetCursor(Avalonia.Platform.IPlatformHandle)' does not exist in the implementation but it does exist in the contract.
+EnumValuesMustMatch : Enum value 'Avalonia.Platform.ExtendClientAreaChromeHints Avalonia.Platform.ExtendClientAreaChromeHints.Default' is (System.Int32)2 in the implementation but (System.Int32)1 in the contract.
 InterfacesShouldHaveSameMembers : Interface member 'public void Avalonia.Platform.ITopLevelImpl.SetCursor(Avalonia.Platform.ICursorImpl)' is present in the implementation but not in the contract.
 InterfacesShouldHaveSameMembers : Interface member 'public void Avalonia.Platform.ITopLevelImpl.SetCursor(Avalonia.Platform.IPlatformHandle)' is present in the contract but not in the implementation.
 MembersMustExist : Member 'public void Avalonia.Platform.ITopLevelImpl.SetCursor(Avalonia.Platform.IPlatformHandle)' does not exist in the implementation but it does exist in the contract.
-Total Issues: 4
+Total Issues: 5

src/Avalonia.Controls/Platform/ExtendClientAreaChromeHints.cs

@@ -16,7 +16,7 @@ namespace Avalonia.Platform
         /// <summary>
         /// The default for the platform.
         /// </summary>
-        Default = SystemChrome,
+        Default = PreferSystemChrome,
 
         /// <summary>
         /// Use SystemChrome

src/Avalonia.Native/avn.idl

@@ -397,7 +397,7 @@ enum AvnExtendClientAreaChromeHints
     AvnSystemChrome = 0x01,
     AvnPreferSystemChrome = 0x02,
     AvnOSXThickTitleBar = 0x08,
-    AvnDefaultChrome = AvnSystemChrome,
+    AvnDefaultChrome = AvnPreferSystemChrome,
 }
 
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