Preserve user's historic route upon rerouting

[danesfeder]

Originally captured in https://github.com/mapbox/mapbox-navigation-android/issues/1595#issue-387034432, this ticket serves to track the visual aspects of tracking historical route progress with the NavigationMapRoute used in the NavigationView.

When an off-route occurs, the complete tracked route geometry can be assembled from Navigator and then drawn on the map, indicating the user is not currently on this route but has traveled those roads thus far.

cc @akitchen

[Guardiola31337]

Is this still something we want to implement @asinghal22?

cc @abhishek1508 @cafesilencio

[stale[bot]]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[Guardiola31337]

Friendly ping @asinghal22

If we're not going to support this for now, feel free to close here.

cc @abhishek1508