### Description

Currently we have a test that verifies auto following behavior regarding leader and follower cluster restart.

However remote cluster is disabled before the leader restart and configured again after:

https://github.com/elastic/elasticsearch/blob/33b3ccaabc6960f02c005b6bc14a1c527a24875b/x-pack/plugin/ccr/src/internalClusterTest/java/org/elasticsearch/xpack/ccr/RestartIndexFollowingIT.java#L92-L96

This happens as leader cluster changes the port during the restart and otherwise would become not accessible.
x-pack/plugin/ccr/src/internalClusterTest/java/org/elasticsearch/xpack/ccr/RestartIndexFollowingIT.java
ensureLeaderGreen("index1");
        
        setupRemoteCluster();
        final long thirdBatchNumDocs = randomIntBetween(10, 200);
        for (int i = 0; i < thirdBatchNumDocs; i++) {
            leaderClient().prepareIndex("index1").setSource("{}", XContentType.JSON).get();
        }
        assertBusy(
            () -> assertThat(
                followerClient().prepareSearch("index2").get().getHits().getTotalHits().value,
                equalTo(firstBatchNumDocs + secondBatchNumDocs + thirdBatchNumDocs)
            )
        );
        cleanRemoteCluster();
        assertAcked(followerClient().execute(PauseFollowAction.INSTANCE, new PauseFollowAction.Request("index2")).actionGet());
        assertAcked(followerClient().admin().indices().prepareClose("index2"));
        final ActionFuture<AcknowledgedResponse> unfollowFuture = followerClient().execute(
            UnfollowAction.INSTANCE,
            new UnfollowAction.Request("index2")
        );
        final ElasticsearchException elasticsearchException = expectThrows(ElasticsearchException.class, unfollowFuture::actionGet);
        assertThat(elasticsearchException.getMessage(), containsString("no such remote cluster"));
        assertThat(elasticsearchException.getMetadataKeys(), hasItem("es.failed_to_remove_retention_leases"));
    }
    private void setupRemoteCluster() throws Exception {
        var remoteMaxPendingConnectionListeners = getRemoteMaxPendingConnectionListeners();
        ClusterUpdateSettingsRequest updateSettingsRequest = new ClusterUpdateSettingsRequest().masterNodeTimeout(TimeValue.MAX_VALUE);
        String address = getLeaderCluster().getAnyMasterNodeInstance(TransportService.class).boundAddress().publishAddress().toString();
        updateSettingsRequest.persistentSettings(Settings.builder().put("cluster.remote.leader_cluster.seeds", address));
        assertAcked(followerClient().admin().cluster().updateSettings(updateSettingsRequest).actionGet());