Set default title and subtitle font sizes

Pretty hacky but it will do for now

lib/android/app/src/main/java/com/reactnativenavigation/presentation/OptionsPresenter.java

 import com.reactnativenavigation.parse.TopTabOptions;
 import com.reactnativenavigation.parse.TopTabsOptions;
 import com.reactnativenavigation.parse.params.Button;
+import com.reactnativenavigation.utils.UiUtils;
 import com.reactnativenavigation.viewcontrollers.IReactView;
 import com.reactnativenavigation.views.Component;
 import com.reactnativenavigation.views.topbar.TopBar;
 public class OptionsPresenter {
     private static final int DEFAULT_TITLE_COLOR = Color.BLACK;
     private static final int DEFAULT_SUBTITLE_COLOR = Color.GRAY;
+    private static final float DEFAULT_TITLE_FONT_SIZE = UiUtils.dpToSp(18);
+    private static final float DEFAULT_SUBTITLE_FONT_SIZE = UiUtils.dpToSp(14);
 
     private TopBar topBar;
 
     }
 
     private void applyTopBarOptions(TopBarOptions options, AnimationsOptions animationOptions, Component component) {
-        if (options.title.text.hasValue()) topBar.setTitle(options.title.text.get());
+        topBar.setTitle(options.title.text.get(""));
         if (options.title.component.hasValue()) topBar.setTitleComponent(options.title.component.get(), options.title.alignment);
-        if (options.title.fontSize.hasValue()) topBar.setTitleFontSize(options.title.fontSize.get());
+        topBar.setTitleFontSize(options.title.fontSize.get(DEFAULT_TITLE_FONT_SIZE));
         topBar.setTitleTextColor(options.title.color.get(DEFAULT_TITLE_COLOR));
         topBar.setTitleTypeface(options.title.fontFamily);
 
-        if (options.subtitle.text.hasValue()) topBar.setSubtitle(options.subtitle.text.get());
-        if (options.subtitle.fontSize.hasValue()) topBar.setSubtitleFontSize(options.subtitle.fontSize.get());
+        topBar.setSubtitle(options.subtitle.text.get(""));
+        topBar.setSubtitleFontSize(options.subtitle.fontSize.get(DEFAULT_SUBTITLE_FONT_SIZE));
         topBar.setSubtitleColor(options.subtitle.color.get(DEFAULT_SUBTITLE_COLOR));
         topBar.setSubtitleFontFamily(options.subtitle.fontFamily);
 

lib/android/app/src/main/java/com/reactnativenavigation/utils/UiUtils.java

         float scale = NavigationApplication.instance.getResources().getDisplayMetrics().density;
         return dp * scale + 0.5f;
     }
+
+    public static float dpToSp(float dp) {
+        return dpToPx(dp) / NavigationApplication.instance.getResources().getDisplayMetrics().density;
+    }
 }