[CI] Use serviceAccountName over serviceAccount

serviceAccount as an attribute has been deprecated and thus Github ARC does
not recognize it. This would mean that the service account we specified did
not actually do anything. Specifying serviceAccountName makes things work
as expected.

Author: boomanaiden154

premerge/linux_runners_values.yaml

@@ -11,7 +11,7 @@ template:
     annotations:
       cluster-autoscaler.kubernetes.io/safe-to-evict: "false"
   spec:
-    serviceAccount: linux-runners-ksa
+    serviceAccountName: linux-runners-ksa
     tolerations:
     - key: "premerge-platform"
       operator: "Equal"

premerge/windows_2022_runner_values.yaml

@@ -11,7 +11,7 @@ template:
     annotations:
       cluster-autoscaler.kubernetes.io/safe-to-evict: "false"
   spec:
-    serviceAccount: windows-runners-ksa
+    serviceAccountName: windows-runners-ksa
     tolerations:
     - key: "node.kubernetes.io/os"
       operator: "Equal"