[jdk24u] RFR: 8347126: gc/stress/TestStressG1Uncommit.java gets OOM-killed

[Satyen Subramaniam]

Backporting JDK-8347126: gc/stress/TestStressG1Uncommit.java gets OOM-killed. Minor change that reduces the memory usage in the `gc/stress/TestStressG1Uncommit.java` test. Ran GHA Sanity Checks, local Tier 1 and Tier 2 tests, and `gc/stress/TestStressG1Uncommit.java`. Patch is clean.

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Commit messages:
 - Backport dff5719e6f95f9ce50a5d49adf13541e22f7b5b1

Changes: https://git.openjdk.org/jdk24u/pull/114/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk24u&pr=114&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8347126
  Stats: 4 lines in 1 file changed: 1 ins; 0 del; 3 mod
  Patch: https://git.openjdk.org/jdk24u/pull/114.diff
  Fetch: git fetch https://git.openjdk.org/jdk24u.git pull/114/head:pull/114

PR: https://git.openjdk.org/jdk24u/pull/114