RFR: 8344177: Remove SecurityManager and related calls from java.management [v6]

[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 two additional commits since the last revision:

 - Remove checkPackageAccess calls
 - Remove Util.check... calls

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/22100/files
  - new: https://git.openjdk.org/jdk/pull/22100/files/9c512b22..16852a03

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=22100&range=05
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=22100&range=04-05

  Stats: 71 lines in 13 files changed: 0 ins; 61 del; 10 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