[jdk25u] RFR: 8358577: Test serviceability/jvmti/thread/GetCurrentContendedMonitor/contmon01/contmon01.java failed: unexpexcted monitor object

[Ian Myers]

Backports the test improvement added by JDK-8358577 in JDK tip (26). Applies cleanly. Affected test
passes. Risk is low: the change is test code only.

-------------

Commit messages:
 - Backport 8f487d26c0f219d4df32be48ff1790e6f98d74a0

Changes: https://git.openjdk.org/jdk25u/pull/7/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk25u&pr=7&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8358577
  Stats: 3 lines in 1 file changed: 1 ins; 1 del; 1 mod
  Patch: https://git.openjdk.org/jdk25u/pull/7.diff
  Fetch: git fetch https://git.openjdk.org/jdk25u.git pull/7/head:pull/7

PR: https://git.openjdk.org/jdk25u/pull/7