RFR: 8297742: Combine vmTestbase/nsk/monitoring/ThreadMXBean/resetPeakThreadCount tests [v2]

[Alex Menkov]

> The fix combines almost the same tests to 1 test to remove code duplication

Alex Menkov has updated the pull request incrementally with one additional commit since the last revision:

  Used multiple test tags

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/11400/files
  - new: https://git.openjdk.org/jdk/pull/11400/files/eba53c1e..393f1252

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=11400&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=11400&range=00-01

  Stats: 27 lines in 1 file changed: 21 ins; 2 del; 4 mod
  Patch: https://git.openjdk.org/jdk/pull/11400.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/11400/head:pull/11400

PR: https://git.openjdk.org/jdk/pull/11400