Added short switch usage with .net 5

src/Services/Catalog/Catalog.API/Controllers/PicController.cs

@@ -56,40 +56,18 @@ namespace Microsoft.eShopOnContainers.Services.Catalog.API.Controllers
 
         private string GetImageMimeTypeFromImageFileExtension(string extension)
         {
-            string mimetype;
-
-            switch (extension)
+            string mimetype = extension switch
             {
-                case ".png":
-                    mimetype = "image/png";
-                    break;
-                case ".gif":
-                    mimetype = "image/gif";
-                    break;
-                case ".jpg":
-                case ".jpeg":
-                    mimetype = "image/jpeg";
-                    break;
-                case ".bmp":
-                    mimetype = "image/bmp";
-                    break;
-                case ".tiff":
-                    mimetype = "image/tiff";
-                    break;
-                case ".wmf":
-                    mimetype = "image/wmf";
-                    break;
-                case ".jp2":
-                    mimetype = "image/jp2";
-                    break;
-                case ".svg":
-                    mimetype = "image/svg+xml";
-                    break;
-                default:
-                    mimetype = "application/octet-stream";
-                    break;
-            }
-
+                ".png" => "image/png",
+                ".gif" => "image/gif",
+                ".jpg" or ".jpeg" => "image/jpeg",
+                ".bmp" => "image/bmp",
+                ".tiff" => "image/tiff",
+                ".wmf" => "image/wmf",
+                ".jp2" => "image/jp2",
+                ".svg" => "image/svg+xml",
+                _ => "application/octet-stream",
+            };
             return mimetype;
         }
     }