Fix condition on font check for Title font change. (#1026)

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

     }
 
     protected void setTitleTextFont(StyleParams params) {
-        if (params.titleBarTitleFont.hasFont()) {
+        if (!params.titleBarTitleFont.hasFont()) {
             return;
         }
         View titleView = getTitleView();