Geo JSONSource Descriptor
In-memory GeoJSON only — set com.xweather.mapsgl.sources.GeoJSONSource.data after com.xweather.mapsgl.map.MapController.addSource. Prefer this constructor over default-arg GeoJSONSourceDescriptor(id = …) when linking against a minified AAR.
Loads GeoJSON from bundledAssetPath under the host app's src/main/assets/ when the source is added. Example: GeoJSONSourceDescriptor("countries", "geojson/conus.geojson").