ContextMenu event is not triggered anymore on a long press on mobile since v1.10

@ansis is already working on this.

Since Dec 10, 2020.

**mapbox-gl-js version**: 1.10 and later

**browser**: Android Chrome 87

### Steps to Trigger Behavior

1. declare a contextmenu event on a map
2. do a long touch on a mobile device
3. contenumenu event is not trigerred anymore since mapbox version 1.10 (it works on v1.9)

### Link to Demonstration

```

mapboxgl.accessToken = 'token';
var map = new mapboxgl.Map({
container: 'map',
style: 'mapbox://styles/mapbox/streets-v11',
})
map.on('contextmenu', () => alert('contextmenu event works'))

```

With mapbox in version 1.9, an alert will be shown if you « long touch » the map on a mobile device.
However, since v1.10 (and until 2.0), the alert won’t be displayed on a long touch on a mobile device.

### Expected Behavior

ContextMenu event is trigerred on a mobile device on a long press.

### Actual Behavior

ContextMenu event is not trigerred on a mobile device on a long press (it works on version 1.9).