Use multiple elasticsearch hosts

Chart version: 7.6.2

Kubernetes provider: E.g. GKE (Google Kubernetes Engine) AWS

Helm Version: 2.16.6

Describe the bug: Trying to set multiple values in the elasticsearchHosts, turns out that is not able to parse the values. I already try to set the value in multiple ways. Could somebody just put a WORKING example of it. Here are some of the formats that I tried:

## Array example 1:
kibana.yml:
  elasticsearchHosts: '["http://es1:9200", "http://es2:9200", "http://es3:9200"]'

## Array example 2:
kibana.yml:
  elasticsearchHosts: ["http://es1:9200", "http://es2:9200", "http://es3:9200"]

## Array example 3:
kibana.yml:
  elasticsearchHosts:
  - http://es1:9200
  - http://es2:9200
  - http://es3:9200

## Array example 4:
kibana.yml:
  elasticsearchHosts:
    http://es1:9200
    http://es2:9200
    http://es3:9200

Expected behavior: The helm is able to parse multiple values as array

Provide logs and/or server output (if relevant):

 FATAL  Error: [config validation of [elasticsearch].hosts]: types that failed validation:
- [config validation of [elasticsearch].hosts.0]: expected URI with scheme [http|https] but got [[http://es1:9200].
- [config validation of [elasticsearch].hosts.1]: expected value of type [array] but got [string]

[Madmaxguy]

Still an issue and also experiencing it

[abuisine]

The solution would be something like this :

elasticsearchHosts: "[\\\"http://192.168.69.61:9200\\\",\\\"http://192.168.69.62:9200\\\",\\\"http://192.168.69.63:9200\\\"]"

I am about to propose a PR as it is insane 😃