RFR: 8349151: Refactor test/java/security//cert/CertificateFactory/slowstream.sh to java test

[Mikhail Yankelevich]

Refactor test/java/security//cert/CertificateFactory/slowstream.sh to java test

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Commit messages:
 - JDK-8349151: Refactor test/java/security//cert/CertificateFactory/slowstream.sh to java test

Changes: https://git.openjdk.org/jdk/pull/23394/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=23394&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8349151
  Stats: 116 lines in 2 files changed: 41 ins; 59 del; 16 mod
  Patch: https://git.openjdk.org/jdk/pull/23394.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/23394/head:pull/23394

PR: https://git.openjdk.org/jdk/pull/23394