RFR: 8344394: Remove SecurityManager and related calls from java.management.rmi [v2]

[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:

  Remove last import sun.reflect.misc.ReflectUtil

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Changes:
  - all: https://git.openjdk.org/jdk/pull/22270/files
  - new: https://git.openjdk.org/jdk/pull/22270/files/3e4a7179..8582eb97

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=22270&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=22270&range=00-01

  Stats: 2 lines in 2 files changed: 0 ins; 2 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/22270.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/22270/head:pull/22270

PR: https://git.openjdk.org/jdk/pull/22270