Expose onConfigurationChanged in ActivityCallbacks. (#769)

android/app/src/main/java/com/reactnativenavigation/controllers/ActivityCallbacks.java

 
 import android.app.Activity;
 import android.content.Intent;
+import android.content.res.Configuration;
 import android.os.Bundle;
 
 public class ActivityCallbacks {
     public void onNewIntent(Intent intent) {
 
     }
+
+    public void onConfigurationChanged(Configuration newConfig) {
+
+    }
 }

android/app/src/main/java/com/reactnativenavigation/controllers/NavigationActivity.java

 
 import android.annotation.TargetApi;
 import android.content.Intent;
+import android.content.res.Configuration;
 import android.os.Build;
 import android.os.Bundle;
 import android.support.annotation.Nullable;
         NavigationApplication.instance.getActivityCallbacks().onNewIntent(intent);
     }
 
+    @Override
+    public void onConfigurationChanged(Configuration newConfig) {
+        super.onConfigurationChanged(newConfig);
+        NavigationApplication.instance.getActivityCallbacks().onConfigurationChanged(newConfig);
+    }
+
     @Override
     protected void onPause() {
         super.onPause();