[core] Revert annotation source maxZoom to 22

src/mbgl/annotation/annotation_source.cpp

@@ -15,8 +15,7 @@ AnnotationSource::Impl::Impl(Source& base_)
 }
 
 Range<uint8_t> AnnotationSource::Impl::getZoomRange() {
-    // Same as default geojson-vt-cpp.
-    return { 0, 18 };
+    return { 0, 22 };
 }
 
 void AnnotationSource::Impl::load(FileSource&) {

src/mbgl/annotation/shape_annotation_impl.cpp

@@ -27,7 +27,7 @@ void ShapeAnnotationImpl::updateTileData(const CanonicalTileID& tileID, Annotati
             return Feature { std::move(geom) };
         }));
         mapbox::geojsonvt::Options options;
-        options.maxZoom = util::clamp<uint8_t>(maxZoom, 0, 18);
+        options.maxZoom = maxZoom;
         options.buffer = 255u;
         options.extent = util::EXTENT;
         options.tolerance = baseTolerance;