Description of problem:

When provisioning a Hosted Control Plane (HCP) BareMetal cluster via ACM, the cluster upgrades option is greyed out in the ACM console. Even after manually setting the update channel in the HostedCluster resource (channel: stable-4.18), the console does not display an option to initiate an upgrade from 4.18.17 to 4.18.18.
This prevents ACM from being a viable management option for HCP clusters since upgrades cannot be initiated through the UI.

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

• ACM version: 2.13.x 

• OpenShift version (HCP cluster): 4.18.17 (attempting to upgrade to 4.18.18)

How reproducible:
Consistently reproducible when creating HCP BareMetal clusters via ACM GUI.

Steps to Reproduce:

1. Provision an HCP BareMetal cluster from ACM GUI.

1. Verify the HostedCluster CR and ensure the channel is set correctly, e.g.:
    
   {{oc get hostedcluster -n <namespace> <clustername> -o yaml | grep channel
   channel: stable-4.18}}
2. Navigate to the ACM console → Clusters → Select the HCP cluster → Attempt to perform an upgrade.

Actual results:

• ACM console shows available updates but the upgrade option is greyed out.

• No button is available in the console to initiate the upgrade.

Expected results:

• ACM console should provide a functional Upgrade button to start the upgrade process from 4.18.17 → 4.18.18.

• Users should not need to edit HostedCluster CRs manually to attempt upgrades.

Additional info:

• Verified that recommended updates are available via oc adm upgrade on the HCP cluster.

• Must-gather, clusterimageset, and managedclusterinfo YAMLs were collected from the customer for further debugging.

• Customer impact: ACM+HCP cannot currently be positioned as a production-ready solution, as upgrades are a critical lifecycle management function.