[jdk17u] RFR: 8271170: Add unit test for what jpackage app launcher puts in the environment

[Andy Herrick]

clean backport of JDK-8271170: Add unit test for what jpackage app launcher puts in the environment

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Commit messages:
 - JDK-8271170: Add unit test for what jpackage app launcher puts in the environment

Changes: https://git.openjdk.java.net/jdk17u/pull/115/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk17u&pr=115&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8271170
  Stats: 330 lines in 7 files changed: 200 ins; 116 del; 14 mod
  Patch: https://git.openjdk.java.net/jdk17u/pull/115.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk17u pull/115/head:pull/115

PR: https://git.openjdk.java.net/jdk17u/pull/115