RFR: 8332161: Test restoring echo in the Console implementation (java.base) [v9]

[Naoto Sato]

> This test intends to verify the behavior of JdkConsole for the java.base module, wrt restoring the echo. The test assumes the internal methods that sets/gets the echo status of the platform.

Naoto Sato has updated the pull request incrementally with one additional commit since the last revision:

  Removed unnecessary add-opens

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Changes:
  - all: https://git.openjdk.org/jdk/pull/19315/files
  - new: https://git.openjdk.org/jdk/pull/19315/files/1c0ab8eb..c583c633

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=19315&range=08
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=19315&range=07-08

  Stats: 1 line in 1 file changed: 0 ins; 1 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/19315.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/19315/head:pull/19315

PR: https://git.openjdk.org/jdk/pull/19315