Heatmap Layer works incorrect in mapbox_maps_flutter package

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I'm trying to add HeatmapLayer using .geojson file and instead of showing heatmap it's just filling in all map with the color that is set as "heatmapColor". However, if I add LineLayer(or any other layer) with same .geojson file it works perfect.

What's wrong with the code below?

```
final data = await rootBundle.loadString(GeojsonFiles.heatmap);
await _controller?.style
.addSource(GeoJsonSource(id: 'heatmap', data: data));

await _controller?.style.addLayer(
HeatmapLayer(
id: 'heatmap_layer',
sourceId: 'heatmap',
heatmapColor: 0xff00ff00,
heatmapOpacity: 0.2,
),
);

await _controller?.style.addLayer(
LineLayer(
id: 'line_layer',
sourceId: 'heatmap',
lineColor: 0xffff0000,
),
);
```

I've tried to change properties of HeatmapLayer class, but nothing changed

Start by reproducing the issue with the shown GeoJsonSource, HeatmapLayer, and LineLayer setup in mapbox_maps_flutter, using the GeojsonFiles.heatmap data. Compare the heatmap rendering with the line rendering and inspect the HeatmapLayer source requirements. Done means the same GeoJSON displays a heatmap rather than filling the map with one color.

Written by the indexing model from the issue text.