Description of problem:

followed https://github.com/rhobs/observability-operator, and installed observability-operator 0.0.15 from console, then create MonitoringStack instance from console, the "Create MonitoringStack" page, default Configure via is: Form view. only see disabled, logLevel settings for alertmanagerConfig, and there are not persistentVolumeClaim/replicas settings for alertmanagerConfig.

NOTE: there are such settings for prometheusConfig.

Version-Release number of selected component (if applicable):

observability-operator 0.0.15

How reproducible:

always

Steps to Reproduce:

1. install observability-operator 0.0.15 from console, then create MonitoringStack instance from console 
2.
3.

Actual results:

there are not persistentVolumeClaim/replicas settings for alertmanager under alertmanagerConfig 

Expected results:

should have such settings

Additional info:

if the result is expected, we could close this bug