[jdk11u-dev] RFR: 8281738: Create a regression test for checking the 'Space' key activation of focused Button

[Goetz Lindenmaier]

I backport this for parity with 11.0.17-oracle.

-------------

Commit messages:
 - Backport 941e97c4eb186bc63386d17f458ba69f4bddd828

Changes: https://git.openjdk.org/jdk11u-dev/pull/1251/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk11u-dev&pr=1251&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8281738
  Stats: 152 lines in 1 file changed: 152 ins; 0 del; 0 mod
  Patch: https://git.openjdk.org/jdk11u-dev/pull/1251.diff
  Fetch: git fetch https://git.openjdk.org/jdk11u-dev pull/1251/head:pull/1251

PR: https://git.openjdk.org/jdk11u-dev/pull/1251