Part of https://github.com/elastic/kibana/issues/153483

We have identified a problem with the index template/ILM policy structure so we need to stop the ILM policy from rolling over while we get a long term fix.

In investigating this I also noticed that the index templates do not set `hidden` to be true which they should.


x-pack/plugin/fleet/src/javaRestTest/java/org/elasticsearch/xpack/fleet/FleetSystemIndicesIT.java
}
    public void testCreationOfFleetPolicies() throws Exception {
        Request request = new Request("PUT", ".fleet-policies");
        Response response = client().performRequest(request);
        assertEquals(200, response.getStatusLine().getStatusCode());
        request = new Request("GET", ".fleet-policies/_mapping");
        response = client().performRequest(request);
        String responseBody = EntityUtils.toString(response.getEntity());
        assertThat(responseBody, containsString("coordinator_idx"));
        request = new Request("GET", ".fleet-policies-7/_mapping");
        response = client().performRequest(request);
        responseBody = EntityUtils.toString(response.getEntity());
        assertThat(responseBody, containsString("coordinator_idx"));
    }
    public void testCreationOfFleetPoliciesLeader() throws Exception {
        Request request = new Request("PUT", ".fleet-policies-leader");
        Response response = client().performRequest(request);
        assertEquals(200, response.getStatusLine().getStatusCode());
        request = new Request("GET", ".fleet-policies-leader/_mapping");
        response = client().performRequest(request);
        String responseBody = EntityUtils.toString(response.getEntity());
        assertThat(responseBody, containsString("server"));
        request = new Request("GET", ".fleet-policies-leader-7/_mapping");
        response = client().performRequest(request);
        responseBody = EntityUtils.toString(response.getEntity());
        assertThat(responseBody, containsString("server"));
    }
    public void testCreationOfFleetServers() throws Exception {
        Request request = new Request("PUT", ".fleet-servers");
        Response response = client().performRequest(request);