Switch to FilterQuality.medium for images (flutter/engine#52984)

https://github.com/flutter/flutter/issues/148253

engine/src/flutter/lib/ui/painting.dart

@@ -3740,7 +3740,7 @@ abstract class ImageFilter {
   /// For example, applying a positive scale matrix (see [Matrix4.diagonal3])
   /// when used with [BackdropFilter] would magnify the background image.
   factory ImageFilter.matrix(Float64List matrix4,
-                     { FilterQuality filterQuality = FilterQuality.low }) {
+                     { FilterQuality filterQuality = FilterQuality.medium }) {
     if (matrix4.length != 16) {
       throw ArgumentError('"matrix4" must have 16 entries.');
     }

engine/src/flutter/lib/web_ui/lib/painting.dart

@@ -439,7 +439,7 @@ class ImageFilter {
   factory ImageFilter.erode({ double radiusX = 0.0, double radiusY = 0.0 }) =>
     engine.renderer.createErodeImageFilter(radiusX: radiusX, radiusY: radiusY);
 
-  factory ImageFilter.matrix(Float64List matrix4, {FilterQuality filterQuality = FilterQuality.low}) {
+  factory ImageFilter.matrix(Float64List matrix4, {FilterQuality filterQuality = FilterQuality.medium}) {
     if (matrix4.length != 16) {
       throw ArgumentError('"matrix4" must have 16 entries.');
     }

engine/src/flutter/testing/dart/painting_test.dart

@@ -6,6 +6,7 @@ import 'dart:typed_data';
 import 'dart:ui';
 
 import 'package:litetest/litetest.dart';
+import 'package:vector_math/vector_math_64.dart';
 
 typedef CanvasCallback = void Function(Canvas canvas);
 
@@ -103,4 +104,12 @@ void main() {
     whitePicture.dispose();
     redClippedPicture.dispose();
   });
+
+  test('ImageFilter.matrix defaults to FilterQuality.medium', () {
+    final Float64List data = Matrix4.identity().storage;
+    expect(
+      ImageFilter.matrix(data).toString(),
+      'ImageFilter.matrix($data, FilterQuality.medium)',
+    );
+  });
 }