fix(ios): Crash "Unexpectedly found nil while implicitly unwrapping an Optional value"

[OS-pedrogustavobilro]

PR description

The crash was occuring inside render method in Map.swift. The creation of GMapView sometimes was occuring after trying to acces it as self.mapViewController.GMapView. In such case the value was still nil, resulting in the crash when trying to unwrap the value.

The fix involved only accessing self.mapViewController.GMapView after viewDidLoad finishes and GMapView is initialized.

Possible fix for #135 and #129 (assuming they are the same issue)

Testing

You may use the example app (e2e-tests) to test and confirm that it does not crash anymore when initializing maps.

I used this block in GMViewController's viewDidLoad to better reproduce the crash:

    override func viewDidLoad() {
        super.viewDidLoad()

        DispatchQueue.main.asyncAfter(deadline: .now() + 3.0) {
            let camera = GMSCameraPosition.camera(withLatitude: self.cameraPosition["latitude"] ?? 0, longitude: self.cameraPosition["longitude"] ?? 0, zoom: Float(self.cameraPosition["zoom"] ?? 12))
            let frame = CGRect(x: self.mapViewBounds["x"] ?? 0, y: self.mapViewBounds["y"] ?? 0, width: self.mapViewBounds["width"] ?? 0, height: self.mapViewBounds["height"] ?? 0)
            if let id = self.mapId {
                let gmsId = GMSMapID(identifier: id)
                self.GMapView = GMSMapView(frame: frame, mapID: gmsId, camera: camera)
            } else {
                self.GMapView = GMSMapView(frame: frame, camera: camera)
            }
            
            self.view = self.GMapView
            self.onViewDidLoad?()
        }
    }