Configure AVP1012 as a warning

.editorconfig

@@ -192,7 +192,7 @@ dotnet_diagnostic.AVP1001.severity = error
 dotnet_diagnostic.AVP1002.severity = error
 dotnet_diagnostic.AVP1010.severity = error
 dotnet_diagnostic.AVP1011.severity = error
-dotnet_diagnostic.AVP1012.severity = error
+dotnet_diagnostic.AVP1012.severity = warning
 dotnet_diagnostic.AVP1013.severity = error
 dotnet_diagnostic.AVP1020.severity = error
 dotnet_diagnostic.AVP1021.severity = error

src/Avalonia.Base/Media/DashStyle.cs

@@ -44,6 +44,8 @@ namespace Avalonia.Media
         /// </summary>
         /// <param name="dashes">The dashes collection.</param>
         /// <param name="offset">The dash sequence offset.</param>
+        [System.Diagnostics.CodeAnalysis.SuppressMessage("AvaloniaProperty", "AVP1012", 
+            Justification = "Collection properties shouldn't be set with SetCurrentValue.")]
         public DashStyle(IEnumerable<double>? dashes, double offset)
         {
             Dashes = (dashes as AvaloniaList<double>) ?? new AvaloniaList<double>(dashes ?? Array.Empty<double>());

src/Avalonia.Base/Media/GradientBrush.cs

@@ -38,6 +38,8 @@ namespace Avalonia.Media
         /// <summary>
         /// Initializes a new instance of the <see cref="GradientBrush"/> class.
         /// </summary>
+        [System.Diagnostics.CodeAnalysis.SuppressMessage("AvaloniaProperty", "AVP1012", 
+            Justification = "Collection properties shouldn't be set with SetCurrentValue.")]
         public GradientBrush()
         {
             this.GradientStops = new GradientStops();

src/Avalonia.Base/Media/PolyLineSegment.cs

@@ -28,6 +28,8 @@ namespace Avalonia.Media
         /// <summary>
         /// Initializes a new instance of the <see cref="PolyLineSegment"/> class.
         /// </summary>
+        [System.Diagnostics.CodeAnalysis.SuppressMessage("AvaloniaProperty", "AVP1012", 
+            Justification = "Collection properties shouldn't be set with SetCurrentValue.")]
         public PolyLineSegment()
         {
             Points = new Points();

src/Avalonia.Base/Media/TransformGroup.cs

@@ -11,6 +11,8 @@ namespace Avalonia.Media
         public static readonly StyledProperty<Transforms> ChildrenProperty =
             AvaloniaProperty.Register<TransformGroup, Transforms>(nameof(Children));
 
+        [System.Diagnostics.CodeAnalysis.SuppressMessage("AvaloniaProperty", "AVP1012", 
+            Justification = "Collection properties shouldn't be set with SetCurrentValue.")]
         public TransformGroup()
         {
             Children = new Transforms();

src/Avalonia.Controls/Documents/Span.cs

@@ -18,6 +18,8 @@ namespace Avalonia.Controls.Documents
             AvaloniaProperty.Register<Span, InlineCollection>(
                 nameof(Inlines));
 
+        [System.Diagnostics.CodeAnalysis.SuppressMessage("AvaloniaProperty", "AVP1012", 
+            Justification = "Collection properties shouldn't be set with SetCurrentValue.")]
         public Span()
         {
             Inlines = new InlineCollection