RFR: 8252377: Incorrect encoding for EC AlgorithmIdentifier

[Hai-May Chao]

This change fixes the DER encoding for ECDSA AlgorithmIdentifier to omit the parameters field instead of encoding a
Null tag.

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Commit messages:
 - 8252377: Incorrect encoding for EC AlgorithmIdentifier

Changes: https://git.openjdk.java.net/jdk/pull/312/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=312&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8252377
  Stats: 217 lines in 2 files changed: 216 ins; 0 del; 1 mod
  Patch: https://git.openjdk.java.net/jdk/pull/312.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/312/head:pull/312

PR: https://git.openjdk.java.net/jdk/pull/312