Align Shapes Fill property behavior with Xamarin.Forms (#10328)

* Align Shapes Fill property behavior with Xamarin.Forms

* Added device tests

src/Core/src/Graphics/ShapeDrawable.cs

@@ -100,10 +100,7 @@ void DrawFillPath(ICanvas canvas, RectF dirtyRect, PathF path)
 		{
 			if (ShapeView == null || ShapeView.Shape == null)
 				return;
-
-			if (!path.Closed)
-				return;
-
+
 			canvas.SaveState();
 
 			canvas.FillColor = Colors.Transparent;

src/Core/tests/DeviceTests/Handlers/ShapeView/ShapeViewHandlerTests.cs

@@ -117,5 +117,26 @@ public async Task PolygonInitializesCorrectly()
 
 			await ValidateNativeFill(polygon, Colors.Lime);
 		}
+
+		[Theory(DisplayName = "Polyline Background Initializes Correctly")]
+		[InlineData(0xFF0000)]
+		[InlineData(0x00FF00)]
+		[InlineData(0x0000FF)]
+		public async Task PolylineBackgroundInitializesCorrectly(uint color)
+		{
+			var expected = Color.FromUint(color);
+
+			var polyline = new ShapeViewStub()
+			{
+				Shape = new PolylineShapeStub { Points = new PointCollectionStub() { new Point(10, 10), new Point(100, 50), new Point(50, 90) } },
+				Stroke = new SolidPaintStub(Colors.Green),
+				Background = new SolidPaintStub(expected),
+				StrokeThickness = 4,
+				Height = 50,
+				Width = 100
+			};
+
+			await ValidateHasColor(polyline, expected);
+		}
 	}
 }