[copilot] Copilot billing/status info in agentic init needs to display AIC-based billing, not premium requests

Copilot has transitioned over to AIC/token based billing but azd is still reporting premium request usage, which is no longer useful to customers.

As part of this I'll check to see if there's any sort of grandfathering happening, where only one would be filled out, but largely I think we'd be fine to just report AIC numbers only.

Once #9644 we should start changing this as part of our general copilot modernization.

(Noted by @JeffreyCA, here: https://github.com/Azure/azure-dev/pull/9644#discussion_r3817722751)