Fix checkstyle-header.txt for current Copyright style

**Auto-cherry-pick to 3.3.x**

Signed-off-by: Soby Chacko <[email protected]>

Author: sobychacko

src/checkstyle/checkstyle-header.txt

@@ -1,5 +1,5 @@
 ^\Q/*\E$
-^\Q * Copyright \E20\d\d(\-20\d\d)?\Q the original author or authors.\E$
+^\Q * Copyright \E20\d\d-present\Q the original author or authors.\E$
 ^\Q *\E$
 ^\Q * Licensed under the Apache License, Version 2.0 (the "License");\E$
 ^\Q * you may not use this file except in compliance with the License.\E$