RFR: 8344337: SecurityManager cleanup in java.prefs moduleRemove SecMgr, etc usage from java.prefs [v2]

[Brent Christian]

> Remove usages of SecurityManager, doPrivildged, and AccessController from the java.prefs module.

Brent Christian has updated the pull request incrementally with one additional commit since the last revision:

  remove commented code + other review feedback

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Changes:
  - all: https://git.openjdk.org/jdk/pull/22252/files
  - new: https://git.openjdk.org/jdk/pull/22252/files/de6717ca..fa0072b7

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=22252&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=22252&range=00-01

  Stats: 197 lines in 6 files changed: 28 ins; 80 del; 89 mod
  Patch: https://git.openjdk.org/jdk/pull/22252.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/22252/head:pull/22252

PR: https://git.openjdk.org/jdk/pull/22252