[jdk17] RFR: 8268349: Provide clear run-time warnings about Security Manager deprecation [v6]

[Weijun Wang]

> More loudly and precise warning messages when a security manager is either enabled at startup or installed at runtime.
> 
> This is new PR for the `openjdk/jdk17` repo copied from https://github.com/openjdk/jdk/pull/4400. A new commit is added.

Weijun Wang has updated the pull request incrementally with one additional commit since the last revision:

  no more null as codeSource, rename one variable

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Changes:
  - all: https://git.openjdk.java.net/jdk17/pull/13/files
  - new: https://git.openjdk.java.net/jdk17/pull/13/files/1e1e7221..885a0072

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk17&pr=13&range=05
 - incr: https://webrevs.openjdk.java.net/?repo=jdk17&pr=13&range=04-05

  Stats: 9 lines in 1 file changed: 6 ins; 0 del; 3 mod
  Patch: https://git.openjdk.java.net/jdk17/pull/13.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk17 pull/13/head:pull/13

PR: https://git.openjdk.java.net/jdk17/pull/13