RFR: 8366486: Test jdk/jfr/event/profiling/TestCPUTimeSampleMultipleRecordings.java is timing out

[Johannes Bechberger]

Fix test case by keeping the sampled thread alive long enough.

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Commit messages:
 - Fix issue

Changes: https://git.openjdk.org/jdk/pull/27053/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=27053&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8366486
  Stats: 8 lines in 1 file changed: 1 ins; 5 del; 2 mod
  Patch: https://git.openjdk.org/jdk/pull/27053.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/27053/head:pull/27053

PR: https://git.openjdk.org/jdk/pull/27053