[jdk17u] RFR: 8275666: serviceability/jvmti/GetObjectSizeClass.java shouldn't have vm.flagless

[Aleksey Shipilev]

Clean backport to fix the test. Effectively reverts a hunk from commit that went in JDK 17.

Additional testing:
 - [x] Affected test still passes

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

Commit messages:
 - Backport cea3f010460c4b45e76bfac8a5b193c49fdd274a

Changes: https://git.openjdk.java.net/jdk17u/pull/236/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk17u&pr=236&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8275666
  Stats: 1 line in 1 file changed: 0 ins; 1 del; 0 mod
  Patch: https://git.openjdk.java.net/jdk17u/pull/236.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk17u pull/236/head:pull/236

PR: https://git.openjdk.java.net/jdk17u/pull/236