RFR: 8313904: [macos] All signing tests which verifies unsigned app images are failing

[Alexey Semenyuk]

On Thu, 10 Aug 2023 22:58:18 GMT, Alexander Matveev <almatvee at openjdk.org> wrote:

> - This is regression from [JDK-8298488](https://bugs.openjdk.org/browse/JDK-8298488).
> - Since JDK-8298488 unsigned app bundles are ad-hoc signed and `codesign` will report that app bundle is signed and thus our tests failed.
> - Fixed tests by checking that all app bundles are signed and by checking how they signed ad-hoc vs actual certificate.
> - Unsigned post process image will be ad-hoc re-sign when generating DMG or PKG, since we adding `.package` file which makes ad-hoc signature invalid. This is similar to [JDK-8293462](https://bugs.openjdk.org/browse/JDK-8293462).

Marked as reviewed by asemenyuk (Reviewer).

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PR Review: https://git.openjdk.org/jdk/pull/15235#pullrequestreview-1573979900