mixed references to both _ios and ios

[rljdavies]

Hi,

As an example in map_view.ios.ts, there seems to be mixed/ambiguous references to _ios and ios. Please see below.

`export class Bounds extends BoundsBase {
    private _ios: GMSCoordinateBounds;

    get ios() {
        return this._ios;
    }

    get southwest() {
        return new Position(this.ios.southWest);
    }

    get northeast() {
        return new Position(this._ios.northEast);
    }

    constructor(ios: GMSCoordinateBounds) {
        super();
        this._ios = ios;
    }

    public static fromCoordinates(southwest: Position, northeast: Position): Bounds {
        return new Bounds(GMSCoordinateBounds.alloc().initWithCoordinateCoordinate(southwest.ios, northeast.ios));
    }`

Worth a tidy?