Return empty Drawable when bridge isn't available (#1360)

android/app/src/main/java/com/reactnativenavigation/react/JsDevImageLoader.java

 import android.graphics.drawable.Drawable;
 import android.os.StrictMode;
 import android.support.annotation.NonNull;
+import android.util.Log;
 
 import com.reactnativenavigation.NavigationApplication;
 
 import java.net.URL;
 
 public class JsDevImageLoader {
-
+    private static final String TAG = "JsDevImageLoader";
     public static Drawable loadIcon(String iconDevUri) {
         try {
             StrictMode.ThreadPolicy threadPolicy = StrictMode.getThreadPolicy();
             StrictMode.setThreadPolicy(threadPolicy);
             return drawable;
         } catch (Exception e) {
-            throw new RuntimeException(iconDevUri, e);
+            Log.e(TAG, "Unable to load icon: " + iconDevUri);
+            return new BitmapDrawable();
         }
     }