RFR: 8370966: Create regression test for the hierarchical memory limit fix in JDK-8370572 [v2]

[Severin Gehwolf]

> Please review this test-only enhancement. It creates a regression test for the Amazon ECS setup on cgroups v1 where the parent memory limit isn't visible inside the container and, thus, needs to rely on the cg v1 specific `hierarchical_memory_limit` token in `memory.stat`. The proposed test is cg v1 only and needs to be run as root. It's skipped otherwise. It's useful to have when working on refactorings like #27743  so as not to regress.
> 
> The other changes are an effort to reduce code duplication in the test code where similar patterns have been used in other container tests.
> 
> Testing (all on Linux x86_64):
> - [x] CG version 2, run as root. Engine: docker. Test is skipped.
> - [x] CG version 1, run as root. Engine: docker. Test passes and fails without the product fix of [JDK-8370572](https://bugs.openjdk.org/browse/JDK-8370572)
> - [x] CG version 1, run as root. Engine: podman. Test passes and fails without the product fix of [JDK-8370572](https://bugs.openjdk.org/browse/JDK-8370572)
> - [X] CG version 1, run as non-root. Test skipped.
> - [x] GHA, though I don't think this is very useful for this change.
> 
> Thoughts?

Severin Gehwolf has updated the pull request incrementally with one additional commit since the last revision:

  Indenting and copyright

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Changes:
  - all: https://git.openjdk.org/jdk/pull/28201/files
  - new: https://git.openjdk.org/jdk/pull/28201/files/86f8e1b8..faeff2a1

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=28201&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=28201&range=00-01

  Stats: 2 lines in 1 file changed: 0 ins; 0 del; 2 mod
  Patch: https://git.openjdk.org/jdk/pull/28201.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/28201/head:pull/28201

PR: https://git.openjdk.org/jdk/pull/28201