RFR: 8310561: JFR: Unify decodeDescriptors(String, String)

[Erik Gahlin]

Could I have a review of a fix that removes duplicated code.

Testing: jdk/jdk/jfr

Thanks
Erik

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Commit messages:
 - Initial

Changes: https://git.openjdk.org/jdk/pull/14598/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=14598&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8310561
  Stats: 53 lines in 2 files changed: 0 ins; 49 del; 4 mod
  Patch: https://git.openjdk.org/jdk/pull/14598.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/14598/head:pull/14598

PR: https://git.openjdk.org/jdk/pull/14598