Assorted jpackage tests fixes: - Fix `JPackageCommand.isFakeRuntime()` on macOS: it failed to identify fully functional runtime, marking all runtimes "fake"; - Add a test for the ExceptionBox class and get 100% coverage of the "jdk.jpackage.internal.util.function" package; - DottedVersionTest: add coverage for `DottedVersion.getComponentsCount()`; - AppVersionTest.java: add validation to the parameter of AppTestSpec ctor; - JPackageCommand.java: make `DEFAULT_RUNTIME_IMAGE` field private; - Convert "switch" statements to expressions and drop redundant "default" clauses where applicable.
- [x] I confirm that I make this contribution in accordance with the [OpenJDK Interim AI Policy](https://openjdk.org/legal/ai). ------------- Commit messages: - Convert "switch" statements to expressions and drop redundant "default" clauses where applicable - JPackageCommand: convert "switch" statements to expressions and drop redundant "default" clauses. - JPackageCommand: make DEFAULT_RUNTIME_IMAGE private - DottedVersionTest: add coverage for DottedVersion.getComponentsCount() - AppVersionTest: add parameter validation to AppTestSpec ctor - ExceptionBoxTest: add missing coverage. With this fix "jdk.jpackage.internal.util.function" package has 100% test coverage. - JPackageCommand: fix isFakeRuntime() on macOS Changes: https://git.openjdk.org/jdk/pull/30510/files Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=30510&range=00 Issue: https://bugs.openjdk.org/browse/JDK-8382684 Stats: 181 lines in 15 files changed: 36 ins; 81 del; 64 mod Patch: https://git.openjdk.org/jdk/pull/30510.diff Fetch: git fetch https://git.openjdk.org/jdk.git pull/30510/head:pull/30510 PR: https://git.openjdk.org/jdk/pull/30510
