Nexus ServiceMonitor uses admin as basicAuth user

added kindbug nexus labels

Throwing this out there...Twistlock is the only other servicemonitor we use with authentication (to my knowledge). Twistlock is a bit different since we created everything to initialize it, but the way that one works:

Metrics user/password is created as a secret, this user has a randomized password
Admin user/password is created as part of init job OR supplied by end user configuration (to handle existing installs)
Init job calls api to create the metrics user with least privilege
Service monitor references the secret for auth

We could likely implement some job logic around things similar to this?

Handle initial password change based on user supplied values or accept user input for password
Create an additional least privilege metrics user
Change servicemonitor to reference ^ user account rather than admin

Would have to evaluate what API calls we have to use, but should be doable?