RFR: 8345286: Remove use of SecurityManager API from misc areas [v2]

[Jaikiran Pai]

> Can I please get a review of this change which removes usages of SecurityManager related APIs and some leftover related to SecurityManager changes?
> 
> This addresses https://bugs.openjdk.org/browse/JDK-8345286. Most of these changes are trivial. The `src/java.base/linux/classes/jdk/internal/platform/CgroupUtil.java` used to expose utility methods for dealing with SecurityManager permissions and it was called from a few places. That class is no longer needed with the clean up done in this PR.
> 
> No new tests have been introduced and tier testing is currently in progress.

Jaikiran Pai has updated the pull request incrementally with four additional commits since the last revision:

 - remove unnecessary space
 - Path.of() instead of Paths.get()
 - fix formatting of try-with-resources in CgroupSubsystemController.java
 - leave out MethodUtil from the clean up

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/22478/files
  - new: https://git.openjdk.org/jdk/pull/22478/files/e36c5207..75511e30

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=22478&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=22478&range=00-01

  Stats: 21 lines in 3 files changed: 7 ins; 1 del; 13 mod
  Patch: https://git.openjdk.org/jdk/pull/22478.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/22478/head:pull/22478

PR: https://git.openjdk.org/jdk/pull/22478