RFR: 8344183: (zipfs) SecurityManager cleanup in the ZipFS area [v3]

[Eirik Bjørsnøs]

> Please review this PR which cleans up SecurityManager-related code following JEP-486 integraion.
> 
> * `ZipFileSystem` is updated to not perform `AccessController::doPrivileged`
> * `ZipFileSystemProvider` is updated to not perform `AccessController::doPrivileged`
> *  The test `TestPosix` is updated to perform `AccessController.doPrivileged`
> 
> This change should be relatively straight-forward to review. Reviewers may want to look extra close at the exception-unwrapping code in `ZipFileSystem::initOwner` and `ZipFileSystem::initGroup`.
> 
> Testing: Tests in `test/jdk/jdk/nio/zipfs` run green locally.

Eirik Bjørsnøs has updated the pull request incrementally with two additional commits since the last revision:

 - Revert catching of NoSuchFileException in expectedDefaultOwner and expectedDefaultGroup
 - Remove @SuppressWarnings("removal")

-------------

Changes:
  - all: https://git.openjdk.org/jdk/pull/22101/files
  - new: https://git.openjdk.org/jdk/pull/22101/files/37104a91..c13e5519

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=22101&range=02
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=22101&range=01-02

  Stats: 6 lines in 3 files changed: 0 ins; 4 del; 2 mod
  Patch: https://git.openjdk.org/jdk/pull/22101.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/22101/head:pull/22101

PR: https://git.openjdk.org/jdk/pull/22101