RFR: 8301793: AlgorithmId should not encode a missing parameters field as NULL unless hardcoded

[Weijun Wang]

Change blocklist to allowlist for encoding null parameters in `AlgorithmId`.

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Commit messages:
 - the fix

Changes: https://git.openjdk.org/jdk/pull/12412/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=12412&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8301793
  Stats: 193 lines in 2 files changed: 121 ins; 21 del; 51 mod
  Patch: https://git.openjdk.org/jdk/pull/12412.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/12412/head:pull/12412

PR: https://git.openjdk.org/jdk/pull/12412