rook: Ceph Octopus: HEALTH_WARN: crush map has legacy tunables (require firefly, min is hammer)

Is this a bug report or feature request?

• Bug Report

Deviation from expected behavior:

[root@kubic-1 /]# ceph status
  cluster:
    id:     0268c660-555c-4fc3-8c56-34386f55ac08
    health: HEALTH_WARN
            crush map has legacy tunables (require firefly, min is hammer)
 
  services:
    mon: 1 daemons, quorum a (age 2m)
    mgr: a(active, since 99s)
    osd: 0 osds: 0 up, 0 in
 
  data:
    pools:   0 pools, 0 pgs
    objects: 0 objects, 0 B
    usage:   0 B used, 0 B / 0 B avail
    pgs:     
 
[root@kubic-1 /]# ceph osd crush dump | jq .tunables
{
  "choose_local_tries": 0,
  "choose_local_fallback_tries": 0,
  "choose_total_tries": 50,
  "chooseleaf_descend_once": 1,
  "chooseleaf_vary_r": 1,
  "chooseleaf_stable": 0,
  "straw_calc_version": 1,
  "allowed_bucket_algs": 22,
  "profile": "firefly",
  "optimal_tunables": 0,
  "legacy_tunables": 0,
  "minimum_required_version": "firefly",
  "require_feature_tunables": 1,
  "require_feature_tunables2": 1,
  "has_v2_rules": 0,
  "require_feature_tunables3": 1,
  "has_v3_rules": 0,
  "has_v4_buckets": 0,
  "require_feature_tunables5": 0,
  "has_v5_rules": 0
}

relates to #743

Expected behavior:

How to reproduce it (minimal and precise):

Environment:

• Cloud provider or hardware configuration: Kubic
• Rook version (use rook version inside of a Rook Pod): 1.0
• Kubernetes version (use kubectl version): 1.14
• Kubernetes cluster type (e.g. Tectonic, GKE, OpenShift): Kubernetes