RFR: 8157173: [macosx] java/awt/Robot/ModifierRobotKey/ModifierRobotKeyTest.java fails [v2]

[Alexander Zvegintsev]

> This test currently passing as it is on all platforms, but it was problemlisted with ["Problem List some tests that leave windows open on the desktop" reason](https://github.com/openjdk/jdk/commit/fd8df3adf13f5df8f5f95482b8e0a70bc519f39f)
> 
> So this test is cleaned up and stabilized.
> 
> CI testing looks good.

Alexander Zvegintsev has updated the pull request incrementally with one additional commit since the last revision:

  Addressing review comments

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/11128/files
  - new: https://git.openjdk.org/jdk/pull/11128/files/8065bbb2..b906399e

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=11128&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=11128&range=00-01

  Stats: 3 lines in 1 file changed: 0 ins; 0 del; 3 mod
  Patch: https://git.openjdk.org/jdk/pull/11128.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/11128/head:pull/11128

PR: https://git.openjdk.org/jdk/pull/11128