[Java][FlightRPC] Flaky test TestDoExchange.tearDown

 
```

[INFO] -------------------------------------------------------
7029[INFO] T E S T S
7030[INFO] -------------------------------------------------------
7031[INFO]
7032[INFO] Results:
7033[INFO]
7034[INFO] Tests run: 0, Failures: 0, Errors: 0, Skipped: 0
7035[INFO]
7036[INFO] Tests run: 8, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 11.249 s - in org.apache.arrow.flight.TestMetadataVersion
7037[INFO] Running org.apache.arrow.flight.TestServerOptions
7038[INFO] Tests run: 5, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 0.034 s - in org.apache.arrow.flight.TestServerOptions
7039[INFO]
7040[INFO] Results:
7041[INFO]
7042Error: Errors:
7043Error: TestDoExchange.tearDown:74 » IllegalState Memory was leaked by query. Memory l...
7044[INFO]
7045Error: Tests run: 107, Failures: 0, Errors: 1, Skipped: 19
```

**Reporter**: [David Li](https://issues.apache.org/jira/browse/ARROW-12233) / @lidavidm
#### Related issues:
- [[CI][Java][Flight] Verify release candidate fails on org.apache.arrow.flight.TestDoExchange](https://github.com/apache/arrow/issues/31694) (is related to)

_{**Note**: *This issue was originally created as [ARROW-12233](https://issues.apache.org/jira/browse/ARROW-12233). Please see the [migration documentation](https://github.com/apache/arrow/issues/14542) for further details.*}

リンクされたCIチェックと74行目のorg.apache.arrow.flight.TestDoExchange.tearDownから始めて、報告されたmemory leakエラーを再現します。繰り返し実行した結果と関連するrelease-candidate issueを比較し、teardownエラーなしでテストが実行され、CIで信頼性を維持できた時点で作業完了とします。

索引モデルが issue の本文から書いたものです。