Update Cluster Manager Node Timeout to 3s for flaky test testHealthOn…

…ClusterManagerFailover (opensearch-project#13505)

Signed-off-by: Rahul Karajgikar <karajgik@amazon.com>
Co-authored-by: Rahul Karajgikar <karajgik@amazon.com>

server/src/internalClusterTest/java/org/opensearch/cluster/ClusterHealthIT.java

@@ -377,7 +377,7 @@ public void testHealthOnClusterManagerFailover() throws Exception {
                     .prepareHealth()
                     .setWaitForEvents(Priority.LANGUID)
                     .setWaitForGreenStatus()
-                    .setClusterManagerNodeTimeout(TimeValue.timeValueMinutes(2))
+                    .setClusterManagerNodeTimeout(TimeValue.timeValueMinutes(3))
                     .execute()
             );
             internalCluster().restartNode(internalCluster().getClusterManagerName(), InternalTestCluster.EMPTY_CALLBACK);