RFR: JDK-8288994: Incorrect @since tags for @value update in JDK-8286101

[Jonathan Gibbons]

Please review a trivial update to correct the values of the @since tags from a recent commit

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Commit messages:
 - JDK-8288994: Incorrect @since tags for @value update in JDK-8286101

Changes: https://git.openjdk.org/jdk/pull/9250/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=9250&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8288994
  Stats: 2 lines in 2 files changed: 0 ins; 0 del; 2 mod
  Patch: https://git.openjdk.org/jdk/pull/9250.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/9250/head:pull/9250

PR: https://git.openjdk.org/jdk/pull/9250