SOLR-6417: OpenCloseCoreStressTest should be much faster on non nightly runs.

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/branches/branch_4x@1620154 13f79535-47bb-0310-9956-ffa450edef68
Merged revision(s) 1620158 from lucene/dev/trunk:
Remove outdated NOTICE.txt entries

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/branches/branch_4x@1620159 13f79535-47bb-0310-9956-ffa450edef68
SOLR-6418: ChaosMonkeySafeLeaderTest is too slow on non nightly runs sometimes.

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/branches/branch_4x@1620164 13f79535-47bb-0310-9956-ffa450edef68