Update Toolbar with correct screen after pop from modal

android/app/src/main/java/com/reactnativenavigation/modal/RnnModal.java

         if (mScreenStack.isEmpty()) {
             dismiss();
         }
-        mToolBar.update(popped);
+        Screen currentScreen = getCurrentScreen();
+        if (currentScreen != null) {
+            mToolBar.update(currentScreen);
+        }
         return popped;
     }
 

android/app/src/main/java/com/reactnativenavigation/views/RnnToolBar.java

 import android.graphics.drawable.Drawable;
 import android.os.AsyncTask;
 import android.support.annotation.ColorInt;
+import android.support.annotation.NonNull;
 import android.support.annotation.UiThread;
 import android.support.v4.content.ContextCompat;
 import android.support.v4.content.res.ResourcesCompat;
     }
 
     private void showToolbar() {
-        ActionBar actionBar = ContextProvider.getActivityContext().getSupportActionBar();
+        ActionBar actionBar = ((AppCompatActivity) getContext()).getSupportActionBar();
         if (actionBar != null) {
             actionBar.show();
         }
     }
 
     private void hideToolbar() {
-        ActionBar actionBar = ContextProvider.getActivityContext().getSupportActionBar();
+        ActionBar actionBar = ((AppCompatActivity) getContext()).getSupportActionBar();
         if (actionBar != null) {
             actionBar.hide();
         }
      * @param screen The currently displayed screen
      */
     @UiThread
-    public void update(Screen screen) {
+    public void update(@NonNull Screen screen) {
         ((AppCompatActivity) getContext()).setSupportActionBar(this);
         setTitle(screen.title);
         setStyle(screen);