RFR: 8283620: System.out does not use the encoding/charset specified in the Javadoc

[Naoto Sato]

Promoting the internal system properties for `System.out` and `System.err` so that users can override the encoding used for those streams to `UTF-8`, aligning to the `Charset.defaultCharset()`. A CSR has also been drafted.

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Commit messages:
 - 8283620: System.out does not use the encoding/charset specified in the Javadoc

Changes: https://git.openjdk.java.net/jdk/pull/8270/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=8270&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8283620
  Stats: 57 lines in 8 files changed: 24 ins; 4 del; 29 mod
  Patch: https://git.openjdk.java.net/jdk/pull/8270.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/8270/head:pull/8270

PR: https://git.openjdk.java.net/jdk/pull/8270