Buses sometimes don't disappear when the route is deselected

[mikeantonacci]

Seems like a timing issue. Need to synchronize the changes to the busicons from the vehicle update observable and the route selection observable. Example logging that demonstrates the issue:

D/RouteSelection: getting both routes: 61B, [61D, 65] D/PatternViewModel$Companion$createPatternSelection: Getting patternSelections: 61B D/BusMapFragment$setupReactiveObjects: removing all 61B's D/BusMapFragment$setupReactiveObjects: REMOVE 6441: com.google.android.gms.maps.model.Marker@8762692 D/BusMapFragment$setupReactiveObjects: Iterating through all vehicles to add V/BusMapFragment$makeBitmaps: using cached bitmap 61B V/BusMapFragment$vehicleUpdateObserver: marker_add adding_marker 6441