[MINOR][BUILD] Enable RAT checking on `LZ4BlockInputStream.java`.

## What changes were proposed in this pull request?

Since `LZ4BlockInputStream.java` is not licensed to Apache Software Foundation (ASF), the Apache License header of that file is not monitored until now.
This PR aims to enable RAT checking on `LZ4BlockInputStream.java` by excluding from `dev/.rat-excludes`.
This will prevent accidental removal of Apache License header from that file.

## How was this patch tested?

Pass the Jenkins tests (Specifically, RAT check stage).

Author: Dongjoon Hyun <dongjoon@apache.org>

Closes #12677 from dongjoon-hyun/minor_rat_exclusion_file.