Fix the Agent default namespace in docs

doc/user/clusters/agent/install/index.md

@@ -104,7 +104,7 @@ Optionally, you can [customize the one-liner installation command](#customize-th
 
 By default, the one-liner command generated by GitLab:
 
-- Creates a namespace for the deployment (`gitlab-kubernetes-agent`).
+- Creates a namespace for the deployment (`gitlab-agent`).
 - Sets up a service account with `cluster-admin` rights (see [how to restrict this service account](#customize-the-permissions-for-the-agentk-service-account)).
 - Creates a `Secret` resource for the agent's registration token.
 - Creates a `Deployment` resource for the `agentk` pod.