[jdk11u-dev] RFR: 8317228: GC: Make TestXXXHeapSizeFlags use createTestJvm

[Andrew Lu]

I backport this for parity with 11.0.25-oracle.

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Commit messages:
 - Backport 7ca0ae94159ac0fd2df23ee1a1e8cf626ce31048

Changes: https://git.openjdk.org/jdk11u-dev/pull/2864/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk11u-dev&pr=2864&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8317228
  Stats: 55 lines in 6 files changed: 40 ins; 5 del; 10 mod
  Patch: https://git.openjdk.org/jdk11u-dev/pull/2864.diff
  Fetch: git fetch https://git.openjdk.org/jdk11u-dev.git pull/2864/head:pull/2864

PR: https://git.openjdk.org/jdk11u-dev/pull/2864