RFR: 8344177: Remove SecurityManager and related calls from java.management [v3]

[Kevin Walls]

> Remove redundant SecurityManager, AccessController references
> (following on from JDK-8338411: Implement JEP 486: Permanently Disable the Security Manager).

Kevin Walls has updated the pull request incrementally with one additional commit since the last revision:

  add back checkClassLoader

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Changes:
  - all: https://git.openjdk.org/jdk/pull/22100/files
  - new: https://git.openjdk.org/jdk/pull/22100/files/f8062515..df6ee04c

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=22100&range=02
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=22100&range=01-02

  Stats: 18 lines in 1 file changed: 15 ins; 0 del; 3 mod
  Patch: https://git.openjdk.org/jdk/pull/22100.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/22100/head:pull/22100

PR: https://git.openjdk.org/jdk/pull/22100