[jdk17u] RFR: 8270946: X509CertImpl.getFingerprint should not return the empty String

[Alexey Bakhtin]

Clean backport of X509CertImpl.getFingerprint issue

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Commit messages:
 - Backport fc80a6b49364594fafa0e2efc769d2f6234cfa22

Changes: https://git.openjdk.java.net/jdk17u/pull/206/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk17u&pr=206&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8270946
  Stats: 228 lines in 6 files changed: 192 ins; 12 del; 24 mod
  Patch: https://git.openjdk.java.net/jdk17u/pull/206.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk17u pull/206/head:pull/206

PR: https://git.openjdk.java.net/jdk17u/pull/206