[Java] Standardise Logger naming

As per: https://github.com/apache/arrow/pull/7100#discussion_r421884919

We use LOGGER and logger interchangeably and should choose one

**Reporter**: [Ryan Murray](https://issues.apache.org/jira/browse/ARROW-8739) / @rymurr

_{**Note**: *This issue was originally created as [ARROW-8739](https://issues.apache.org/jira/browse/ARROW-8739). Please see the [migration documentation](https://github.com/apache/arrow/issues/14542) for further details.*}

先查看所引用的 pull request 討論，然後在 Java repository 中搜尋 LOGGER 和 logger 的使用位置，以確定受影響的檔案。完成的標準是專案始終一致地使用一種 logger 命名慣例；issue 中未提及任何特定的測試或測試檔案。

由索引模型根據 Issue 內容生成。