Feature request: Expanding metrics retention

Metrics supports a reduced fidelity tier > 30 days, but the explore UX shows an error when trying to select a greater range. We should make it clear that it is an option, but that reduces fidelity.

### Problem Statement

Hi. I created a support case recently to allow increasing the retention period for metrics.

> Hi team. We've been using the metrics product and really like it. However, 30 days of retention is not good enough for us since we want to be able to look at trends (we're ok with metrics beyond 30 days to be aggregated on broader intervals if this makes storage easier).
>
> I don't see a way to upgrade metrics (seems like it's still in beta). Is there any way that we can get this expanded?

The suggestion was to file an feature request here. Let me know if you need more information.

### Solution Brainstorm

*No response*

### Product Area

Explore

Start in the Explore area and trace the metrics range-selection flow, including how retention beyond 30 days is represented. Verify the behavior by selecting a range greater than 30 days: the option should be available and clearly explain the reduced fidelity instead of showing an error.

Written by the indexing model from the issue text.