android: splash view unit test

android/app/src/test/java/com/reactnativenavigation/NavigationActivityTest.java

 package com.reactnativenavigation;
 
+import com.reactnativenavigation.views.NavigationSplashView;
+
 import org.junit.Test;
 import org.robolectric.Robolectric;
 
     @Test
     public void showsSplashView() throws Exception {
         NavigationActivity activity = Robolectric.setupActivity(NavigationActivity.class);
-        assertThat(activity).isNotNull();
+        assertThat(activity.getContentView()).isInstanceOf(NavigationSplashView.class);
     }
 }