Disable proactive rerouting, route refreshing after map matching

[1ec5]

The “Custom Server” example relies on the Map Matching API to derive a route from a series of waypoints. This example is intended for a “Bring Your Own Route” use case where the waypoints are control points from a route produced by another routing engine. In that case, proactive rerouting would automatically undo any customization implemented through the BYOR workflow. The route refreshing functionality added in mapbox/mapbox-navigation-ios#2284 would also fail because the route doesn’t come from the Directions API but is instead synthesized on the client-side.

The navigation SDK has no way to distinguish a Route obtained through Directions.calculateRoutes(matching:completionHandler:) from one obtained through calculate(_:completionHandler:). So it falls to the developer to disable proactive rerouting and route refreshing manually:

let router = navigationViewController.navigationService.router
router.reroutesProactively = false
router.refreshesRoute = false

We should add these lines to the “Custom Server” example:

https://github.com/mapbox/navigation-ios-examples/blob/e85b6f530e7b6a0e9fe8f18f5d22472323e43eb7/Navigation-Examples/Examples/Custom-Server.swift#L30-L33

/cc @mapbox/navigation-ios