ambari create ranger user amb_ranger_admin with User role

[Lian Jiang]

I am using HDP3.0 + ambari2.7 to create a hadoop cluster. Ambari creates
amb_ranger_admin in ranger with User role which don't have permission to
create ranger repositories. I have to manually change it to Admin role to
make blueprint automation run through. Is it by design to create
amb_ranger_admin with User role? Can I make ambari to create this user with
Admin role? Thanks.