Topology metrics view has graph window that's dynamic but metrics along bottom are always averaged over 15m

**Old UI or New UI**
New UI (Consul 1.10.1)

**Describe the problem you're having**

The topology UI has a window of ~5m~ (**edit: after further investigation–see below–it's actually dynamic**) for the graph but the metrics along the bottom are averaged over 15m. This can be somewhat confusing. In my screenshot above, I've had a solid 1 RPS for the last 5 minutes but the RPS metric on the bottom is 0.29 RPS since it's only been 1 RPS for the last 5m, not the full 15m.

**Describe the solution you'd like**
I think it would make sense for the time ranges to match. I'm not sure which is best between 5m or 15m, I think it more just matters that it's consistent.

Start in the Consul topology UI by reproducing the mismatch between the graph window and the bottom metrics, then trace how each time range is selected. Confirm the intended range with maintainers and verify that the graph and metrics display values over the same window.

Written by the indexing model from the issue text.