RFR: 8344149: Remove usage of Security Manager from java.rmi [v2]

[Stuart Marks]

> First cut at removal of Security Manager stuff from RMI.
> 
> This covers just about every SM-related case in RMI, except for a bit of package checking in MarshalInputStream. This will be handled separately. It's covered by [JDK-8344329](https://bugs.openjdk.org/browse/JDK-8344329).
> 
> Further simplifications could be done in RuntimeUtil and NewThreadAction. However, those changes started to become somewhat more intrusive than I'd like for this PR, which is focused on removing security-related stuff. EDIT: I've filed [JDK-8344461](https://bugs.openjdk.org/browse/JDK-8344461) to cover this additional cleanup work.

Stuart Marks has updated the pull request incrementally with one additional commit since the last revision:

  Update with changes from code review.

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/22129/files
  - new: https://git.openjdk.org/jdk/pull/22129/files/1e7e88a7..f8e63868

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=22129&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=22129&range=00-01

  Stats: 8 lines in 2 files changed: 1 ins; 1 del; 6 mod
  Patch: https://git.openjdk.org/jdk/pull/22129.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/22129/head:pull/22129

PR: https://git.openjdk.org/jdk/pull/22129