In 7.12, Maps added support for geometry-collections stored in Elasticsearch.

GeoJson upload does not support GeometryCollections. It breaks in two ways:
- the layer-preview breaks because the label-centroid calculation throws when encountering a geometry-collection
- the upload to elasticsearch fails because the geometries array is not correctly set

To close the loop on this, and remove this odd breakage, GeoJson-upload should support geometry-collections.