bug in StringBuilderConstantParameters fixer

[nakulj]

What happened?

Correctly spots a StringBuilderConstantParameters here, but suggests an incorrect fix:

new StringBuilder(foo)
  .append("_")
  .append(bar)
  .toString()
  .toLowerCase();

Suggestion:

foo + "_" + bar.toLowerCase();

What did you want to happen?

(foo + "_" + bar).toLowerCase();