Check for Mapbox#INSTANCE when initializing the MapView

[LukasPaczos]

Checks for the missing configuration right away. Previously, when Mapbox#geInstance wasn't called before the view's inflation, the app would crash with the UnsatisfiedLinkError:

2019-04-08 16:15:43.759 16541-16541/com.mapbox.mapboxsdk.testapp E/AndroidRuntime: FATAL EXCEPTION: main
    Process: com.mapbox.mapboxsdk.testapp, PID: 16541
    java.lang.RuntimeException: Unable to start activity ComponentInfo{com.mapbox.mapboxsdk.testapp/com.mapbox.mapboxsdk.testapp.activity.maplayout.SimpleMapActivity}: android.view.InflateException: Binary XML file line #9: Binary XML file line #9: Error inflating class com.mapbox.mapboxsdk.maps.MapView
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2778)
        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2856)
        at android.app.ActivityThread.-wrap11(Unknown Source:0)
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1589)
        at android.os.Handler.dispatchMessage(Handler.java:106)
        at android.os.Looper.loop(Looper.java:164)
        at android.app.ActivityThread.main(ActivityThread.java:6494)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:438)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:807)
     Caused by: android.view.InflateException: Binary XML file line #9: Binary XML file line #9: Error inflating class com.mapbox.mapboxsdk.maps.MapView
     Caused by: android.view.InflateException: Binary XML file line #9: Error inflating class com.mapbox.mapboxsdk.maps.MapView
     Caused by: java.lang.reflect.InvocationTargetException
        at java.lang.reflect.Constructor.newInstance0(Native Method)
        at java.lang.reflect.Constructor.newInstance(Constructor.java:334)
        at android.view.LayoutInflater.createView(LayoutInflater.java:647)
        at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:790)
        at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:730)
        at android.view.LayoutInflater.rInflate(LayoutInflater.java:863)
        at android.view.LayoutInflater.rInflateChildren(LayoutInflater.java:824)
        at android.view.LayoutInflater.inflate(LayoutInflater.java:515)
        at android.view.LayoutInflater.inflate(LayoutInflater.java:423)
        at android.view.LayoutInflater.inflate(LayoutInflater.java:374)
        at android.support.v7.app.AppCompatDelegateImplV9.setContentView(AppCompatDelegateImplV9.java:287)
        at android.support.v7.app.AppCompatActivity.setContentView(AppCompatActivity.java:139)
        at com.mapbox.mapboxsdk.testapp.activity.maplayout.SimpleMapActivity.onCreate(SimpleMapActivity.java:19)
        at android.app.Activity.performCreate(Activity.java:7009)
        at android.app.Activity.performCreate(Activity.java:7000)
        at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1214)
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2731)
        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2856)
        at android.app.ActivityThread.-wrap11(Unknown Source:0)
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1589)
        at android.os.Handler.dispatchMessage(Handler.java:106)
        at android.os.Looper.loop(Looper.java:164)
        at android.app.ActivityThread.main(ActivityThread.java:6494)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:438)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:807)
     Caused by: java.lang.UnsatisfiedLinkError: No implementation found for void com.mapbox.mapboxsdk.maps.renderer.MapRenderer.nativeInitialize(com.mapbox.mapboxsdk.maps.renderer.MapRenderer, float, java.lang.String, java.lang.String) (tried Java_com_mapbox_mapboxsdk_maps_renderer_MapRenderer_nativeInitialize and Java_com_mapbox_mapboxsdk_maps_renderer_MapRenderer_nativeInitialize__Lcom_mapbox_mapboxsdk_maps_renderer_MapRenderer_2FLjava_lang_String_2Ljava_lang_String_2)
        at com.mapbox.mapboxsdk.maps.renderer.MapRenderer.nativeInitialize(Native Method)
        at com.mapbox.mapboxsdk.maps.renderer.MapRenderer.<init>(MapRenderer.java:43)
        at com.mapbox.mapboxsdk.maps.renderer.glsurfaceview.GLSurfaceViewMapRenderer.<init>(GLSurfaceViewMapRenderer.java:29)
        at com.mapbox.mapboxsdk.maps.MapView$5.<init>(MapView.java:301)
2019-04-08 16:15:43.759 16541-16541/com.mapbox.mapboxsdk.testapp E/AndroidRuntime:     at com.mapbox.mapboxsdk.maps.MapView.initialiseDrawingSurface(MapView.java:301)
        at com.mapbox.mapboxsdk.maps.MapView.initialize(MapView.java:144)
        at com.mapbox.mapboxsdk.maps.MapView.<init>(MapView.java:101)
        	... 26 more