[iOS][Credential-Provider] Show service as title

Bug: 1090772
Change-Id: I8b2b483b308b36800ab03415aabab84f2b8c7640
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2239576
Commit-Queue: Javier Ernesto Flores Robles <javierrobles@chromium.org>
Reviewed-by: David Jean <djean@chromium.org>
Cr-Commit-Position: refs/heads/master@{#777322}

ios/chrome/credential_provider_extension/ui/credential_list_view_controller.mm

@@ -178,9 +178,9 @@ const CGFloat kHeaderHeight = 70;
   }
   cell.imageView.contentMode = UIViewContentModeScaleAspectFit;
   cell.accessoryView.backgroundColor = [UIColor colorNamed:kBackgroundColor];
-  cell.textLabel.text = credential.user;
+  cell.textLabel.text = credential.serviceName;
   cell.textLabel.textColor = [UIColor colorNamed:kTextPrimaryColor];
-  cell.detailTextLabel.text = credential.serviceName;
+  cell.detailTextLabel.text = credential.user;
   cell.detailTextLabel.textColor = [UIColor colorNamed:kTextSecondaryColor];
   cell.selectionStyle = UITableViewCellSelectionStyleNone;