Correct the unit of file size from "kb" (maybe "kilo bits") to "KB" (#76033)

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

@@ -502,7 +502,7 @@ void paintImage({
           exception: 'Image $debugImageLabel has a display size of '
             '$outputWidth×$outputHeight but a decode size of '
             '${image.width}×${image.height}, which uses an additional '
-            '${overheadInKilobytes}kb.\n\n'
+            '${overheadInKilobytes}KB.\n\n'
             'Consider resizing the asset ahead of time, supplying a cacheWidth '
             'parameter of $outputWidth, a cacheHeight parameter of '
             '$outputHeight, or using a ResizeImage.',

packages/flutter/test/painting/paint_image_test.dart

@@ -101,7 +101,7 @@ void main() {
 
     expect(
       messages.single,
-      'Image TestImage has a display size of 200×100 but a decode size of 300×300, which uses an additional 364kb.\n\n'
+      'Image TestImage has a display size of 200×100 but a decode size of 300×300, which uses an additional 364KB.\n\n'
       'Consider resizing the asset ahead of time, supplying a cacheWidth parameter of 200, a cacheHeight parameter of 100, or using a ResizeImage.',
     );