RFR: 8273853: Update the Java manpage for automatic CDS archive updating

[Ioi Lam]

Added description of the new flag `-XX:+AutoCreateSharedArchive` to the `java` man page.

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Commit messages:
 - 8273853: Update the Java manpage for automatic CDS archive updating

Changes: https://git.openjdk.java.net/jdk/pull/9024/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=9024&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8273853
  Stats: 34 lines in 1 file changed: 31 ins; 0 del; 3 mod
  Patch: https://git.openjdk.java.net/jdk/pull/9024.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/9024/head:pull/9024

PR: https://git.openjdk.java.net/jdk/pull/9024