RFR: 8369501: Parallel: Add UseAdaptiveSizePolicy requirement to TestDynShrinkHeap.java

[Albert Mingkun Yang]

Add a `@requires` to this test so that it will be skipped if `UseAdaptiveSizePolicy` is off.

Test: tier1-3

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Commit messages:
 - jtreg-flag

Changes: https://git.openjdk.org/jdk/pull/27724/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=27724&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8369501
  Stats: 2 lines in 2 files changed: 2 ins; 0 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/27724.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/27724/head:pull/27724

PR: https://git.openjdk.org/jdk/pull/27724