### 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
}
        return settings.build();
    }
    public void testFollowIndex() throws Exception {
        final String leaderIndexSettings = getIndexSettings(randomIntBetween(1, 10), 0);
        assertAcked(leaderClient().admin().indices().prepareCreate("index1").setSource(leaderIndexSettings, XContentType.JSON));
        ensureLeaderGreen("index1");
        setupRemoteCluster();
        final PutFollowAction.Request followRequest = putFollow("index1", "index2");
        if (randomBoolean()) {
            followRequest.getParameters().setMaxReadRequestOperationCount(randomIntBetween(5, 10));
        }
        followerClient().execute(PutFollowAction.INSTANCE, followRequest).get();
        final long firstBatchNumDocs = randomIntBetween(10, 200);
        logger.info("Indexing [{}] docs as first batch", firstBatchNumDocs);
        for (int i = 0; i < firstBatchNumDocs; i++) {
            final String source = String.format(Locale.ROOT, "{\"f\":%d}", i);
            leaderClient().prepareIndex("index1").setId(Integer.toString(i)).setSource(source, XContentType.JSON).get();
        }
        assertBusy(
            () -> assertThat(followerClient().prepareSearch("index2").get().getHits().getTotalHits().value, equalTo(firstBatchNumDocs))
        );
        getFollowerCluster().fullRestart();
        ensureFollowerGreen("index2");
        final long secondBatchNumDocs = randomIntBetween(10, 200);
        for (int i = 0; i < secondBatchNumDocs; i++) {
            leaderClient().prepareIndex("index1").setSource("{}", XContentType.JSON).get();
        }
        cleanRemoteCluster();
        getLeaderCluster().fullRestart();