Fix rollover being mistaken to happen twice

This is not the case because we upgrade from 7.17 to 8.19, which
contains the change to the template already. So when we upgrade again to
9.1, it will not rollover.

See elastic/elasticsearch#119995.

Author: ericywl

functionaltests/9_x_test.go

@@ -124,19 +124,12 @@ func managedThenUpgrade789Runner(fromVersion7, toVersion8, toVersion9 ecclient.S
 		"metrics-apm.transaction.1m-%s":         checkILM,
 	}
 
-	checkILMRolloverTwice := asserts.CheckDataStreamIndividualWant{
-		PreferIlm:        true,
-		DSManagedBy:      managedByILM,
-		IndicesManagedBy: []string{managedByILM, managedByILM, managedByILM},
-	}
-
 	check9 := map[string]asserts.CheckDataStreamIndividualWant{
-		// These data streams are rolled over in 8.x, so with the 9.x rollover
-		// there will be 3 indices per DS.
-		"traces-apm-%s":                     checkILMRolloverTwice,
-		"metrics-apm.app.opbeans_python-%s": checkILMRolloverTwice,
-		"metrics-apm.internal-%s":           checkILMRolloverTwice,
-		"logs-apm.error-%s":                 checkILMRolloverTwice,
+		// These data streams are already rolled over in 8.x.
+		"traces-apm-%s":                     checkILMRollover,
+		"metrics-apm.app.opbeans_python-%s": checkILMRollover,
+		"metrics-apm.internal-%s":           checkILMRollover,
+		"logs-apm.error-%s":                 checkILMRollover,
 		// These data streams are only created in 8.x, so they will only be
 		// rolled over once.
 		"metrics-apm.service_destination.1m-%s": checkILMRollover,