RouteLineDistancesIndex.getPoint() NullPointerException

Nobody has claimed this yet.

### Steps to trigger behavior

Unknown at this time. I just ran into it while testing on the main branch.

### Issue

```
2020-10-26 12:10:21.310 9969-9969/com.mapbox.navigation.examples E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.mapbox.navigation.examples, PID: 9969
java.lang.NullPointerException: Attempt to invoke virtual method 'com.mapbox.geojson.Point com.mapbox.navigation.ui.route.RouteLineDistancesIndex.getPoint()' on a null object reference
at com.mapbox.navigation.ui.route.MapRouteLine.updateTraveledRouteLine(MapRouteLine.kt:1052)
at com.mapbox.navigation.ui.route.NavigationMapRoute$1.onIndicatorPositionChanged(NavigationMapRoute.java:343)
at com.mapbox.mapboxsdk.location.LocationComponent$10.onIndicatorPositionChanged(LocationComponent.java:1880)
at com.mapbox.mapboxsdk.location.LocationLayerController$1.onNewAnimationValue(LocationLayerController.java:269)
at com.mapbox.mapboxsdk.location.LocationLayerController$1.onNewAnimationValue(LocationLayerController.java:265)
at com.mapbox.mapboxsdk.location.MapboxAnimator.postUpdates(MapboxAnimator.java:106)
at com.mapbox.mapboxsdk.location.MapboxAnimator.onAnimationUpdate(MapboxAnimator.java:93)
at android.animation.ValueAnimator.animateValue(ValueAnimator.java:1566)
at android.animation.ValueAnimator.animateBasedOnTime(ValueAnimator.java:1357)
at android.animation.ValueAnimator.doAnimationFrame(ValueAnimator.java:1489)
at android.animation.ValueAnimator.pulseAnimationFrame(ValueAnimator.java:1508)
at android.animation.AnimatorSet.pulseFrame(AnimatorSet.java:1170)
at android.animation.AnimatorSet.doAnimationFrame(AnimatorSet.java:1061)
at android.animation.AnimationHandler.doAnimationFrame(AnimationHandler.java:146)
at android.animation.AnimationHandler.access$100(AnimationHandler.java:37)
at android.animation.AnimationHandler$1.doFrame(AnimationHandler.java:54)
at android.view.Choreographer$CallbackRecord.run(Choreographer.java:970)
at android.view.Choreographer.doCallbacks(Choreographer.java:796)
at android.view.Choreographer.doFrame(Choreographer.java:727)
```

Start at MapRouteLine.kt:1052, where updateTraveledRouteLine triggers the null dereference, and trace the callback from NavigationMapRoute.java:343 through the location callbacks. Establish a reproducible route-update scenario from the stack trace, then verify that indicator updates no longer crash when the distance index is unavailable.

Written by the indexing model from the issue text.