Description of problem:

Not able to scale out the nodes if changing count parameter in environment file.

I have defined below parameter in network-environment.yaml file, if I am changing the node count from here nodes are not getting scaledout I have to explicitly change the "CountDefault" in roles file. 

I know that we have removed the CLI option for scaleout, can't we scaleout the nodes by mentioning the count parameter in a single file instead of changing the default value in roles definition file. 

~~~
parameter_defaults:
  ExternalNetCidr: '10.11.48.0/24'
  ExternalAllocationPools: [{'start': '10.11.48.181', 'end': '10.11.48.190'}]
  ExternalNetworkVlanID: 10
  ExternalInterfaceDefaultRoute: '10.11.48.254'
  InternalApiNetCidr: '192.168.124.0/24'
  TenantNetCidr: '192.168.123.0/24'
  StorageNetCidr: '192.168.125.0/24'
  StorageMgmtNetCidr: '192.168.128.0/24'
  InternalApiAllocationPools: [{'start': '192.168.124.20', 'end': '192.168.124.200'}]
  TenantAllocationPools: [{'start': '192.168.123.20', 'end': '192.168.123.200'}]
  StorageAllocationPools: [{'start': '192.168.125.20', 'end': '192.168.125.200'}]
  StorageMgmtAllocationPools: [{'start': '192.168.128.30', 'end': '192.168.128.60'}]
  # Leave room for floating IPs in the External allocation pool
  InternalApiNetworkVlanID: 30
  StorageNetworkVlanID: 20
  StorageMgmtNetworkVlanID: 40
  TenantNetworkVlanID: 50
  ControlPlaneDefaultRoute: 192.0.2.1
  EC2MetadataIp: 192.0.2.1
  NeutronExternalNetworkBridge: "''"
  ControllerCount: 1
  ComputeCount: 1
  NetworkerCount: 1
~~~

Version-Release number of selected component (if applicable):
RHEL OSP 10

How reproducible:
Everytime. 

Steps to Reproduce:
1. Make changes for count parameter in environment file.
2. Try to perform the scaleout. 
3. Nothing changed. 

Actual results:


Expected results:


Additional info: