Correct name in DecorationImage error string (#47260)

packages/flutter/lib/src/painting/decoration_image.dart

@@ -222,7 +222,7 @@ class DecorationImagePainter {
         // when the image is ready.
         if (configuration.textDirection == null) {
           throw FlutterError.fromParts(<DiagnosticsNode>[
-            ErrorSummary('ImageDecoration.matchTextDirection can only be used when a TextDirection is available.'),
+            ErrorSummary('DecorationImage.matchTextDirection can only be used when a TextDirection is available.'),
             ErrorDescription(
               'When DecorationImagePainter.paint() was called, there was no text direction provided '
               'in the ImageConfiguration object to match.'

packages/flutter/test/painting/decoration_test.dart

@@ -257,7 +257,7 @@ void main() {
     expect(error.diagnostics[3], isInstanceOf<DiagnosticsProperty<ImageConfiguration>>());
     expect(error.toStringDeep(),
       'FlutterError\n'
-      '   ImageDecoration.matchTextDirection can only be used when a\n'
+      '   DecorationImage.matchTextDirection can only be used when a\n'
       '   TextDirection is available.\n'
       '   When DecorationImagePainter.paint() was called, there was no text\n'
       '   direction provided in the ImageConfiguration object to match.\n'