[CI] FullClusterRestartIT testTransportCompressionSetting failing

[tlrx]

This test fails in BWC tests for versions on 6.x

Build scan:
https://gradle-enterprise.elastic.co/s/pm2j47oz4vqfu/tests/:qa:full-cluster-restart:v6.1.3%23oldClusterTest/org.elasticsearch.upgrades.FullClusterRestartIT/testTransportCompressionSetting

https://gradle-enterprise.elastic.co/s/ndabyfvb3mmc2
https://gradle-enterprise.elastic.co/s/hlyrme6numsms
https://gradle-enterprise.elastic.co/s/m5xq2nx5dia3k
(and many more)

Reproduction line:
./gradlew ':qa:full-cluster-restart:v6.1.3#oldClusterTest' -Dtests.class="org.elasticsearch.upgrades.FullClusterRestartIT" -Dtests.method="testTransportCompressionSetting" -Dtests.seed=91E9022443DDE03 -Dtests.bwc=true -Dtests.locale=es-US -Dtests.timezone=Asia/Kolkata -Druntime.java=8

Applicable branches:
7.x

Reproduces locally?:
Didn't try

Failure history:
https://gradle-enterprise.elastic.co/scans/tests?tests.container=org.elasticsearch.upgrades.FullClusterRestartIT&tests.test=testTransportCompressionSetting

Failure excerpt:

org.elasticsearch.client.ResponseException: method [PUT], host [http://[::1]:42923], URI [/_cluster/settings], status line [HTTP/1.1 400 Bad Request]
{"error":{"root_cause":[{"type":"remote_transport_exception","reason":"[v6.1.3-1][127.0.0.1:45267][cluster:admin/settings/update]"}],"type":"illegal_argument_exception","reason":"persistent setting [cluster.remote.foo.seeds], not recognized"},"status":400}

  at __randomizedtesting.SeedInfo.seed([91E9022443DDE03:B7EE2D6F8305F9E1]:0)
  at org.elasticsearch.client.RestClient.convertResponse(RestClient.java:326)
  at org.elasticsearch.client.RestClient.performRequest(RestClient.java:296)
  at org.elasticsearch.client.RestClient.performRequest(RestClient.java:270)
  at org.elasticsearch.upgrades.FullClusterRestartIT.testTransportCompressionSetting(FullClusterRestartIT.java:1693)
  at sun.reflect.NativeMethodAccessorImpl.invoke0(NativeMethodAccessorImpl.java:-2)
  at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
  at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
  at java.lang.reflect.Method.invoke(Method.java:498)
  at com.carrotsearch.randomizedtesting.RandomizedRunner.invoke(RandomizedRunner.java:1750)
  at com.carrotsearch.randomizedtesting.RandomizedRunner$8.evaluate(RandomizedRunner.java:938)
  at com.carrotsearch.randomizedtesting.RandomizedRunner$9.evaluate(RandomizedRunner.java:974)
  at com.carrotsearch.randomizedtesting.RandomizedRunner$10.evaluate(RandomizedRunner.java:988)
  at com.carrotsearch.randomizedtesting.rules.StatementAdapter.evaluate(StatementAdapter.java:36)
  at org.apache.lucene.util.TestRuleSetupTeardownChained$1.evaluate(TestRuleSetupTeardownChained.java:49)
  at org.apache.lucene.util.AbstractBeforeAfterRule$1.evaluate(AbstractBeforeAfterRule.java:45)
  at org.apache.lucene.util.TestRuleThreadAndTestName$1.evaluate(TestRuleThreadAndTestName.java:48)
  at org.apache.lucene.util.TestRuleIgnoreAfterMaxFailures$1.evaluate(TestRuleIgnoreAfterMaxFailures.java:64)
  at org.apache.lucene.util.TestRuleMarkFailure$1.evaluate(TestRuleMarkFailure.java:47)
  at com.carrotsearch.randomizedtesting.rules.StatementAdapter.evaluate(StatementAdapter.java:36)
  at com.carrotsearch.randomizedtesting.ThreadLeakControl$StatementRunner.run(ThreadLeakControl.java:368)
  at com.carrotsearch.randomizedtesting.ThreadLeakControl.forkTimeoutingTask(ThreadLeakControl.java:817)
  at com.carrotsearch.randomizedtesting.ThreadLeakControl$3.evaluate(ThreadLeakControl.java:468)
  at com.carrotsearch.randomizedtesting.RandomizedRunner.runSingleTest(RandomizedRunner.java:947)
  at com.carrotsearch.randomizedtesting.RandomizedRunner$5.evaluate(RandomizedRunner.java:832)
  at com.carrotsearch.randomizedtesting.RandomizedRunner$6.evaluate(RandomizedRunner.java:883)
  at com.carrotsearch.randomizedtesting.RandomizedRunner$7.evaluate(RandomizedRunner.java:894)
  at org.apache.lucene.util.AbstractBeforeAfterRule$1.evaluate(AbstractBeforeAfterRule.java:45)
  at com.carrotsearch.randomizedtesting.rules.StatementAdapter.evaluate(StatementAdapter.java:36)
  at org.apache.lucene.util.TestRuleStoreClassName$1.evaluate(TestRuleStoreClassName.java:41)
  at com.carrotsearch.randomizedtesting.rules.NoShadowingOrOverridesOnMethodsRule$1.evaluate(NoShadowingOrOverridesOnMethodsRule.java:40)
  at com.carrotsearch.randomizedtesting.rules.NoShadowingOrOverridesOnMethodsRule$1.evaluate(NoShadowingOrOverridesOnMethodsRule.java:40)
  at com.carrotsearch.randomizedtesting.rules.StatementAdapter.evaluate(StatementAdapter.java:36)
  at com.carrotsearch.randomizedtesting.rules.StatementAdapter.evaluate(StatementAdapter.java:36)
  at com.carrotsearch.randomizedtesting.rules.StatementAdapter.evaluate(StatementAdapter.java:36)
  at org.apache.lucene.util.TestRuleAssertionsRequired$1.evaluate(TestRuleAssertionsRequired.java:53)
  at org.apache.lucene.util.TestRuleMarkFailure$1.evaluate(TestRuleMarkFailure.java:47)
  at org.apache.lucene.util.TestRuleIgnoreAfterMaxFailures$1.evaluate(TestRuleIgnoreAfterMaxFailures.java:64)
  at org.apache.lucene.util.TestRuleIgnoreTestSuites$1.evaluate(TestRuleIgnoreTestSuites.java:54)
  at com.carrotsearch.randomizedtesting.rules.StatementAdapter.evaluate(StatementAdapter.java:36)
  at com.carrotsearch.randomizedtesting.ThreadLeakControl$StatementRunner.run(ThreadLeakControl.java:368)
  at java.lang.Thread.run(Thread.java:748)

[elasticmachine]

Pinging @elastic/es-distributed (Team:Distributed)

[Tim-Brooks]

Fixed by #74790