RFR: 8255206: [macos] LicenseTest fails on macOS 11

[Alexander Matveev]

I did not reproduce issue with license is not shown as per SQE report. It work as expected. However, jpackage fails due to unflatten/flatten being removed from hdiutil on macOS 11. I am not sure why it was needed, probably some legacy code. Without unflatten/flatten everything works as expected on macOS 11 and 10.5.7.

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Commit messages:
 - 8255206: [macos] LicenseTest fails on macOS 11

Changes: https://git.openjdk.java.net/jdk/pull/847/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=847&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8255206
  Stats: 18 lines in 1 file changed: 0 ins; 18 del; 0 mod
  Patch: https://git.openjdk.java.net/jdk/pull/847.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/847/head:pull/847

PR: https://git.openjdk.java.net/jdk/pull/847