apmpackage: support phases (warm, cold) in ILM in apm package

right now, built-in ILM policies with APM package don't use Warm/Cold nodes type

it will be good to support them

ideally APM package should support all customisation which ApmServer k8s CRD have

for example

```
apiVersion: apm.k8s.elastic.co/v1
kind: ApmServer
metadata:
name: xxxx
spec:
...
elasticsearchRef:
name: xxx
kibanaRef:
name: xxx
config:
logging.level: warning
logging.json: true
setup:
dashboards.enabled: true
ilm:
enabled: true
overwrite: true
policy_file: "ilm-policy.json"
template:
settings:
index:
number_of_shards: 8
number_of_replicas: 2
```