[jdk20u] RFR: 8306825: Monitor deflation might be accidentally disabled by zero intervals

[Aleksey Shipilev]

Clean backport to improve both new code for `GuaranteedAsyncDeflationInterval`, but also handles bugs in existing intervals handling.

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Depends on: https://git.openjdk.org/jdk20u/pull/70

Commit messages:
 - Backport a6b4f25bd50e6861281d162f143c5bc9c16bac51

Changes: https://git.openjdk.org/jdk20u/pull/71/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk20u&pr=71&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8306825
  Stats: 619 lines in 4 files changed: 383 ins; 231 del; 5 mod
  Patch: https://git.openjdk.org/jdk20u/pull/71.diff
  Fetch: git fetch https://git.openjdk.org/jdk20u.git pull/71/head:pull/71

PR: https://git.openjdk.org/jdk20u/pull/71