Pull the box-drawing-character trick again.

...to address a http://errorprone.info/bugpattern/UnicodeEscape warning.

PiperOrigin-RevId: 906376496

Author: cpovirk

core/src/test/java/com/google/googlejavaformat/java/JavadocFormattingTest.java

@@ -1338,7 +1338,7 @@ class Test {}
   @Test
   public void unicodeEscapesNotInterpretedBug() {
     /*
-     * In theory, \u003C should be treated exactly like <, and so too should the escaped versions of
+     * In theory, ╲u003C should be treated exactly like <, and so too should the escaped versions of
      * @, *, and other special chars. We don't recognize that, though, so we don't put what is
      * effectively "<p>" on a new line.
      */