[HOLD for payment 2025-01-28] [HOLD for payment 2025-01-17] Reduce string unions in Route type

[mountiny]

Problem

Similarly, as we had to do in this PR #40418, we are again running into an issue with an excess of string unions in the Route type. You can see full explanation in the PR there.

### Solution

Update the types to reduce the number of unions so the TS is working fine.

Issue Owner

Current Issue Owner: @isabelastisser

[melvin-bot]

Triggered auto assignment to @isabelastisser (Bug), see https://stackoverflow.com/c/expensify/questions/14418 for more details. Please add this bug to a GH project, as outlined in the SO.

[fabioh8010]

I'm Fábio from Callstack - expert agency contributor - and I would like to work on this issue.

[fabioh8010]

PR was merged, will proceed with the small follow up soon