Unable to set heading or pitch of map view on load

[1ec5]

When setting the camera within -[MGLMapViewDelegate mapView:didFinishLoadingStyle:] or -[MGLMapViewDelegate mapViewDidFinishLoadingMap:], MGLMapView no longer respects the camera’s heading or pitch. The following code results in a map centered at the correct coordinate and at the correct zoom level, but at a pitch of 0° and a heading just off of 0°:

- (void)mapViewDidFinishLoadingMap:(MGLMapView *)mapView {
    MGLMapCamera *camera = [MGLMapCamera cameraLookingAtCenterCoordinate:CLLocationCoordinate2DMake(39.10279795, -84.5064623336961) acrossDistance:50 pitch:60 heading:45];
    mapView.camera = camera;
}

This issue reproduces in iOS map SDK v4.6.0-alpha.2 and also da2685d on both iOS and macOS, whether or not there’s animation when setting the camera, in both iosapp and the iOS examples project. It does not reproduce in iOS map SDK v4.5.0.

This issue removes the principal workaround for #3859, which is that you can’t set the camera earlier in -[UIViewController viewDidLoad].

/cc @mapbox/maps-ios

[1ec5]

I’m guessing this is fallout from #13123.