Maneuver expansion + voice

It would be great to add the maneuver -> announcement expansion work that @alianthes @mcwhittemore and @hdaymon are working on to this UI as a way to preview the results. We can also add voice announcements using Polly like we using the Navigation SDK.

Start by locating the UI mentioned in the issue and reviewing how the Navigation SDK handles maneuver announcements. Check the related maneuver-to-announcement work by @alianthes, @mcwhittemore, and @hdaymon, then determine how Polly voice announcements should be previewed. Done means the UI previews expanded maneuver announcements and supports voice announcements.

Written by the indexing model from the issue text.