Found a few dead code spots in macOS jpackage code that would be good to clean up. Likely leftovers from refactoring.

There is an "INSTALLER_SUFFIX" bundler param defined for PKG and DMG bundlers at [1] and [2]. They both default to empty strings, and I don't see how the default values are overridden. They can be safely removed.

Branching at [3] is:
---
} else if (OperatingSystem.isMacOS()) {
    signAppBundle(params, root, "-", null, null);
} else {
    // Calling signAppBundle() without signingIdentity will result in
    // unsigning app bundle
    signAppBundle(params, root, null, null, null);
}
---
This branching is in macOS-specific class, it doesn't make sense because OperatingSystem.isMacOS() always evaluates to "true" if the code execution gets to this point.

[1] https://github.com/openjdk/jdk/blob/bad39b6d8892ba9b86bc81bf01108a1df617defb/src/jdk.jpackage/macosx/classes/jdk/jpackage/internal/MacPkgBundler.java#L143
[2] https://github.com/openjdk/jdk/blob/bad39b6d8892ba9b86bc81bf01108a1df617defb/src/jdk.jpackage/macosx/classes/jdk/jpackage/internal/MacDmgBundler.java#L68
[3] https://github.com/openjdk/jdk/blob/618c5eb27b4c719afd577b690e6bcb21a45fcb0d/src/jdk.jpackage/macosx/classes/jdk/jpackage/internal/MacAppImageBuilder.java#L422