RFR: 8292177: InitialSecurityProperty JFR event [v5]

[Sean Coffey]

> New JFR event to record state of initial security properties.
>  
> Debug output is also now added for these properties via -Djava.security.debug=properties

Sean Coffey has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains 17 commits:

 - test update
 - Merge branch 'master' into secEvent-8292177
 - Use stringPropertyNames()
 - Refactor getter method name
 - Restore ProtectionDomain to original
 - Store properties cache in Security class
 - Remove unused import
 - Address Oct 10 review comments
 - Check for 0 security events
 - Null check on Properties
 - ... and 7 more: https://git.openjdk.org/jdk/compare/3644e26c...3a347dae

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Changes: https://git.openjdk.org/jdk/pull/10394/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=10394&range=04
  Stats: 255 lines in 12 files changed: 252 ins; 0 del; 3 mod
  Patch: https://git.openjdk.org/jdk/pull/10394.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/10394/head:pull/10394

PR: https://git.openjdk.org/jdk/pull/10394