If you have a management user in your AS7 server that you can provide to RHQ, just enter the credentials into the AS7 resource's Inventory->Connection Settings configuration in the RHQ UI. If you don't have such user set up, you can use the "Install RHQ user" operation on the AS7 resource in RHQ UI. This will install a new management user in your AS7 server and you can then use the credentials you provided to that operation in the Connection Settings of the AS7 resource.
It works. Thank you!