RFR: 8344397: Remove Security Manager dependencies from java.security and sun.security packages [v6]

[Sean Mullan]

> Now that JEP 486 has been integrated, `java.security` and `sun.security` implementation dependencies on `System.getSecurityManager` and `AccessController.doPrivileged` can be removed. 
> 
> This should cover most of the remaining cleanup in the security libraries area. A couple of the `sun.security.action` classes can't be removed yet, as well as a few constants in `sun.security.util.SecurityConstants` and internal `ProtectionDomain` methods until dependencies are removed in other areas. Some additional test cleanup can also be done later.

Sean Mullan has updated the pull request incrementally with one additional commit since the last revision:

  Remove trailing whitespace.

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Changes:
  - all: https://git.openjdk.org/jdk/pull/22418/files
  - new: https://git.openjdk.org/jdk/pull/22418/files/fdc7dfd3..de301fbf

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=22418&range=05
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=22418&range=04-05

  Stats: 3 lines in 1 file changed: 0 ins; 0 del; 3 mod
  Patch: https://git.openjdk.org/jdk/pull/22418.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/22418/head:pull/22418

PR: https://git.openjdk.org/jdk/pull/22418