Fix testAutoExpandIndicesDuringRollingUpgrade (elastic#50427)

Fixes the muted test "testAutoExpandIndicesDuringRollingUpgrade". We can't wait in the test for
the index to be green, as we have put a filter exclusion into place that prevents all shards from
being allocated after a node rejoins. Instead we check whether the correct auto-expansion has
taken place.

Closes elastic#50426

Author: ywelsch

qa/rolling-upgrade/src/test/java/org/elasticsearch/upgrades/RecoveryIT.java

@@ -775,7 +775,6 @@ public void testTurnOffTranslogRetentionAfterUpgraded() throws Exception {
         }
     }
 
-    @AwaitsFix(bugUrl = "https://github.com/elastic/elasticsearch/issues/50426")
     public void testAutoExpandIndicesDuringRollingUpgrade() throws Exception {
         final String indexName = "test-auto-expand-filtering";
         final Version minimumNodeVersion = minimumNodeVersion();
@@ -796,12 +795,11 @@ public void testAutoExpandIndicesDuringRollingUpgrade() throws Exception {
                 Settings.builder().put(IndexMetaData.INDEX_ROUTING_EXCLUDE_GROUP_PREFIX + "._id", nodes.get(randomInt(2))));
         }
 
-        ensureGreen(indexName);
-
         final int numberOfReplicas = Integer.parseInt(
             getIndexSettingsAsMap(indexName).get(IndexMetaData.SETTING_NUMBER_OF_REPLICAS).toString());
         if (minimumNodeVersion.onOrAfter(Version.V_7_6_0)) {
             assertEquals(nodes.size() - 2, numberOfReplicas);
+            ensureGreen(indexName);
         } else {
             assertEquals(nodes.size() - 1, numberOfReplicas);
         }