[CI] testRetentionLeaseIsRenewedDuringRecovery fails

[dnhatn]

CcrRetentionLeaseIT#testRetentionLeaseIsRenewedDuringRecovery is failing frequently.

Some CI instances:

• https://elasticsearch-ci.elastic.co/job/elastic+elasticsearch+master+periodic/744/console
• https://elasticsearch-ci.elastic.co/job/elastic+elasticsearch+master+internalClusterTest/1383/console
• https://elasticsearch-ci.elastic.co/job/elastic+elasticsearch+master+periodic/744/console

FAILURE 21.4s J4 | CcrRetentionLeaseIT.testRetentionLeaseIsRenewedDuringRecovery <<< FAILURES!
   > Throwable #1: java.lang.AssertionError: 
   > Expected: a value greater than <1550430923773L>
   >      but: <1550430923773L> was equal to <1550430923773L>
   > 	at org.hamcrest.MatcherAssert.assertThat(MatcherAssert.java:20)
   > 	at org.elasticsearch.xpack.ccr.CcrRetentionLeaseIT.lambda$testRetentionLeaseIsRenewedDuringRecovery$3(CcrRetentionLeaseIT.java:269)
   > 	at org.elasticsearch.test.ESTestCase.assertBusy(ESTestCase.java:858)
   > 	at org.elasticsearch.test.ESTestCase.assertBusy(ESTestCase.java:832)
   > 	at org.elasticsearch.xpack.ccr.CcrRetentionLeaseIT.testRetentionLeaseIsRenewedDuringRecovery(CcrRetentionLeaseIT.java:253)
   > 	at java.lang.Thread.run(Thread.java:748)

Relates #38829

[elasticmachine]

Pinging @elastic/es-distributed

[dnhatn]

I have muted this test in master, 7.x, 7.0 and 6.7.

[jasontedor]

Thanks @dnhatn, I will take a look soon.

[benwtrent]

@jasontedor it seems that the fix did not work, or made another issues visible.

https://elasticsearch-ci.elastic.co/job/elastic+elasticsearch+master+internalClusterTest/1654/console