Xamarin.Forms.GoogleMaps Shows green screen on emulator

hi,
i am trying to use Xamarin.Forms.GoogleMaps nuget in a xamarin.forms project but all i get is a green screen with "Xamarin.Forms.GoogleMaps" text in the middle on my emulator

this is the app.cs

    public App()
        {
            // The root page of your application
            var content = new ContentPage
            {
                Title = "GoogleTestApps",
                Content = new StackLayout
                {
                    VerticalOptions = LayoutOptions.FillAndExpand,
                    Children = {
                        new Map(MapSpan.FromCenterAndRadius(new Position(30.0444, 31.2357), new Distance(200))) {
                            VerticalOptions = LayoutOptions.StartAndExpand,
                            HorizontalOptions = LayoutOptions.FillAndExpand,
                            HeightRequest = 920,
                            WidthRequest = 400,
                            MapType = MapType.Street
                        }
                    }
                }
            };

            MainPage = new NavigationPage(content);
        }

and this is my AndroidManifest file
<manifest xmlns:android="http://schemas.android.com/apk/res/android" android:installLocation="auto"> <uses-sdk android:minSdkVersion="15" /> <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" /> <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" /> <uses-permission android:name="android.permission.ACCESS_LOCATION_EXTRA_COMMANDS" /> <uses-permission android:name="android.permission.ACCESS_MOCK_LOCATION" /> <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" /> <uses-permission android:name="android.permission.ACCESS_WIFI_STATE" /> <uses-permission android:name="android.permission.INTERNET" /> <application android:label="GoogleTestApps.Droid"> <meta-data android:name="com.google.android.maps.v2.API_KEY" android:value="Key" /> <meta-data android:name="com.google.android.gms.version" android:value="@integer/google_play_services_version" /> </application> </manifest>

this is what is shown on the emulator