default floating_ip_enabled in cluster_template creation form is false in the UI but is set to true in the backend

While creating a new cluster template, in the `cluster_template` creation form, `floating_ip_enabled` defaults to unchecked i.e `False` in the UI. But when the `cluster_template` gets created, the value of `floating_ip_enabled` is set to True.

Analysis:
- When sending the cluster_template create request, `floating_ip_enabled` key was not present in the payload (because it was not updated by the user) and `floating_ip_enabled` gets set to true in the backend.
- When the `floating_ip_enabled` option is checked, and then unchecked, there is no issue as `floating_ip_enabled` key is sent in the payload and has a value of `False`.

So the is issue only when the `floating_ip_enabled` key is not present in the payload and magnum assumes the default value as `True` for `floating_ip_enabled` in the backend. It leads to an inconsistent UX.

Therefore, the floating_ip_enabled should default to the `checked` state (i.e True) in the UI (consistent with backend).