AsyncSearchActionIT.testTermsAggregation failures in master

[jkakavas]

Build scan:

Repro line:

./gradlew ':x-pack:plugin:async-search:internalClusterTest' --tests "org.elasticsearch.xpack.search.AsyncSearchActionIT.testTermsAggregation" \
  -Dtests.seed=DC511A34397367E2 \
  -Dtests.security.manager=true \
  -Dtests.locale=ja \
  -Dtests.timezone=America/Curacao \
  -Druntime.java=11

Reproduces locally?: Yes, 4 times in 200 iterations

Applicable branches: master

Failure history: Once a day , since August 27th https://build-stats.elastic.co/app/kibana#/discover?_g=(refreshInterval:(pause:!t,value:0),time:(from:now-90d,mode:quick,to:now))&_a=(columns:!(branch),index:e58bf320-7efd-11e8-bf69-63c8ef516157,interval:auto,query:(language:lucene,query:testTermsAggregation),sort:!(time,desc)) --> Failure excerpt:

org.elasticsearch.xpack.search.AsyncSearchActionIT > testTermsAggregation FAILED
    java.lang.AssertionError: 
    Expected: <INTERNAL_SERVER_ERROR>
         but: was <NOT_FOUND>
        at __randomizedtesting.SeedInfo.seed([DC511A34397367E2:1332157DC294FFEA]:0)
        at org.hamcrest.MatcherAssert.assertThat(MatcherAssert.java:18)
        at org.junit.Assert.assertThat(Assert.java:956)
        at org.junit.Assert.assertThat(Assert.java:923)
        at org.elasticsearch.xpack.search.AsyncSearchIntegTestCase$2.doNext(AsyncSearchIntegTestCase.java:280)
        at org.elasticsearch.xpack.search.AsyncSearchIntegTestCase$2.next(AsyncSearchIntegTestCase.java:256)
        at org.elasticsearch.xpack.search.AsyncSearchIntegTestCase$2.next(AsyncSearchIntegTestCase.java:243)
        at org.elasticsearch.xpack.search.AsyncSearchActionIT.testTermsAggregation(AsyncSearchActionIT.java:145)

[elasticmachine]

Pinging @elastic/es-search (:Search/Search)

[javanna]

looks very similar to #61790

[jimczi]

That's a duplicate that we'll solve in #61790, hence closing