RFR: 8286172: Create an automated test for JDK-4516019

[Srinivas Mandalika]

Create an automated test for [JDK-4516019](https://bugs.openjdk.java.net/browse/JDK-4516019)

Clicking on the increment/decrement buttons of the spinner does not install focus on the spinner or one of its focusable children.

The test validates the same.

This review is for migrating tests from a closed test suite to open.

Testing:
The test ran successfully on Mach5 with multiple runs (30) on windows-x64, linux-x64 and macos-x64.

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Commit messages:
 - Whitespace error fixed.
 - 8286172: Create an automated test for JDK-4516019

Changes: https://git.openjdk.java.net/jdk/pull/8546/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=8546&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8286172
  Stats: 122 lines in 1 file changed: 122 ins; 0 del; 0 mod
  Patch: https://git.openjdk.java.net/jdk/pull/8546.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/8546/head:pull/8546

PR: https://git.openjdk.java.net/jdk/pull/8546