Update Anchore values to support different VS name for SSO

https://repo1.dso.mil/platform-one/big-bang/bigbang/-/blob/master/chart/templates/anchore/values.yaml#L36

Currently we hardcode the prefix here to anchore. However, someone can override the anchore prefix here via values:

addons:
  anchore:
    values:
      istio:
        ui:
          hosts:
            - "myanchore.{{ .Values.hostname }}"

This would result in the automated SSO setup failing unless the customer specific overrides acsUrl in their values.

We can "better" automate this by doing a dig to see if the user has overridden the value above (addons.anchore.values.istio.ui.hosts), then grabbing the first value from the list and using that for part of the acsUrl (replacing the anchore.{{ .Values.hostname }} section).

A good way to test this is to override the hostname value yourself with something like the above example and validate that SSO is still successfully set up. Also ensure that when not providing a host value it works as expected.

AC:

• BB anchore values yaml updated to accommodate customer override of hostname