core: set correct entity id when importing template

When importing a template, the entity id should be set to the imported
template id rather then the specific disk id, otherwise the end method
will run as first disk finishes, but the import hasn't been done yet.

Change-Id: I7b08c91bf3caf4faec0da9e10adf360dad16e2ac
Signed-off-by: Liron Aravot <laravot@redhat.com>