Simple code cleanup. This was added back in [JDK 13](https://github.com/openjdk/jdk/commit/71825293eb83d7c9ac122c11a12465c2acbec040) and should have an `@since`
------------- Commit messages: - add an `@since` and modify Copyright header Changes: https://git.openjdk.org/jdk/pull/19190/files Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=19190&range=00 Issue: https://bugs.openjdk.org/browse/JDK-8332100 Stats: 3 lines in 1 file changed: 2 ins; 0 del; 1 mod Patch: https://git.openjdk.org/jdk/pull/19190.diff Fetch: git fetch https://git.openjdk.org/jdk.git pull/19190/head:pull/19190 PR: https://git.openjdk.org/jdk/pull/19190
