RFR: 8267047: Put serviceability/sa/TestJmapCoreMetaspace.java back on ZGC problem list due to JDK-8267045

[Chris Plummer]

[JDK-8267045](https://bugs.openjdk.java.net/browse/JDK)-8267045 removed this test from the ZGC problem list, but it still fails, so it needs to be re-added.

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Commit messages:
 - ProblemList serviceability/sa/TestJmapCoreMetaspace.java

Changes: https://git.openjdk.java.net/jdk/pull/4002/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=4002&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8267047
  Stats: 1 line in 1 file changed: 1 ins; 0 del; 0 mod
  Patch: https://git.openjdk.java.net/jdk/pull/4002.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/4002/head:pull/4002

PR: https://git.openjdk.java.net/jdk/pull/4002