[jdk17u] RFR: 8274523: java/lang/management/MemoryMXBean/MemoryTest.java test should handle Shenandoah

[Aleksey Shipilev]

Clean backport to fix another test for Shenandoah.

Additional testing:
 - [x] Linux x86_64 fastdebug, affected test now passes with Shenandoah

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Commit messages:
 - Backport f8415a9b2f610ed431e6948c8174f6d982e5b31f

Changes: https://git.openjdk.java.net/jdk17u/pull/238/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk17u&pr=238&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8274523
  Stats: 2 lines in 1 file changed: 0 ins; 0 del; 2 mod
  Patch: https://git.openjdk.java.net/jdk17u/pull/238.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk17u pull/238/head:pull/238

PR: https://git.openjdk.java.net/jdk17u/pull/238