Android Foreground Notification

[Archdoog]

To ensure the navigation foreground service is accepted by Android review, we need to include a foreground service notification. This is typically an active notification with the upcoming maneuver.

For a good example:

1. Start navigation on Google Maps on android,
2. Background the app (e.g. lock the phone)

At this point you will see google maps actively progressing toward the next maneuver as a foreground notification.

This should follow #113