RFR: 8373086: Make isexceeded001.java more robust

[Joel Sikström]

On Thu, 4 Dec 2025 09:30:49 GMT, Albert Mingkun Yang <ayang at openjdk.org> wrote:

> The original intended fix is to increase initial-heap-size so avoid gc, captured in [JDK-8373022](https://bugs.openjdk.org/browse/JDK-8373022). This is an alternative, which makes the test more resilient to changes in heaps/gcs.
> 
> Running `vmTestbase/nsk/monitoring/MemoryPoolMBean/isUsageThresholdExceeded/isexceeded002/TestDescription.java`
> with `-XX:+UseParallelGC -Xcomp -XX:-TieredCompilation -XX:InitialRAMPercentage=0` fails about 10% of the time.
> 
> After applying the fix, `isexceeded002` passes 2,000 runs.

Looks good. Interesting test bug.

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Marked as reviewed by jsikstro (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/28655#pullrequestreview-3539044879