[Annotations] Arrow doesn't show up until user draws another annotation

[trbmcginnis]

When a user draws their first annotation, the arrows will not fully show up (sometimes there's one arrow, sometimes there's none).

Zooming in and out will make the arrows disappear and reappear.

The arrows on that first annotation will show up permanently when:

• User draws another annotation
• User relabels a zoning district

[trbmcginnis]

An example where one arrow showed up:

[trbmcginnis]

An example where no arrows showed up:

[hannahkates]

They also appear/disappear depending on the zoom level, without drawing a new annotation. See gif below

[ghost]

oh weird! maybe this can be fixed with just styling ! great catch, @hannahkates

[chriswhong]

I believe this is due to the image for the arrowhead not being added to the map in time.

The icon gets added using https://docs.mapbox.com/mapbox-gl-js/api/#map#addimage, I am not sure how, but I think we need to confirm that it's available before trying to render things that use it.

[hannahkates]

Closing, looks like this was fixed successfully.