RFR: 8304911: Use OperatingSystem enum in some modules [v2]

[Roger Riggs]

> With the addition of `jdk.internal.util.OperatingSystem` references to the system property `os.name` can be replaced.
> This PR exports jdk.internal.util to:
>  - java.prefs,
>  - java.security.jgss,
>  - java.smartcardio,
>  - jdk.charsets,
>  - jdk.net,
>  - jdk.zipfs

Roger Riggs has updated the pull request incrementally with one additional commit since the last revision:

  Revert chanes to ZipFileSystem to defer refactoring.
  Reformatted expression to match switch expression formatting.

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Changes:
  - all: https://git.openjdk.org/jdk/pull/13335/files
  - new: https://git.openjdk.org/jdk/pull/13335/files/72cff1ed..aadf5bbd

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=13335&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=13335&range=00-01

  Stats: 11 lines in 2 files changed: 3 ins; 2 del; 6 mod
  Patch: https://git.openjdk.org/jdk/pull/13335.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/13335/head:pull/13335

PR: https://git.openjdk.org/jdk/pull/13335