install: Add dedicated ServiceAccount for console plugin

Platform pods must not use the default service account, per the
no-default-service-account-operator-checker monitor test. Add a
dedicated ServiceAccount and reference it in the deployment.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: jhadvig

install/0000_50_cluster-update-console-plugin_15_serviceaccount.yaml

@@ -0,0 +1,11 @@
+apiVersion: v1
+kind: ServiceAccount
+metadata:
+  name: cluster-update-console-plugin
+  namespace: openshift-cluster-update-console-plugin
+  annotations:
+    kubernetes.io/description: The OpenShift cluster-update console plugin provides a web-console interface for managing ClusterVersion updates.
+    capability.openshift.io/name: Console
+    release.openshift.io/feature-set: TechPreviewNoUpgrade
+    exclude.release.openshift.io/internal-openshift-hosted: "true"
+    include.release.openshift.io/self-managed-high-availability: "true"

install/0000_50_cluster-update-console-plugin_50_deployment.yaml

@@ -26,6 +26,7 @@ spec:
       labels:
         app: cluster-update-console-plugin
     spec:
+      serviceAccountName: cluster-update-console-plugin
       automountServiceAccountToken: false
       containers:
       - name: plugin