RFR: 8281296: Create a regression test for JDK-4515999

[Manukumar V S]

On Mon, 7 Feb 2022 08:18:23 GMT, Manukumar V S <mvs at openjdk.org> wrote:

> Create a regression test for [JDK-4515999](https://bugs.openjdk.java.net/browse/JDK-4515999)
> Create a test which checks whether incrementing dates via the keyboard (up/down) gives the same results as when using mouse press on the arrow buttons in a JSpinner.

@aivanov-jdk Can you please review this?

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PR: https://git.openjdk.java.net/jdk/pull/7363