currentScreen not updating - fixed & center fields

app/src/main/java/info/nightscout/androidaps/startupwizard/SetupWizardActivity.java

@@ -141,6 +141,7 @@ public class SetupWizardActivity extends AppCompatActivity {
         List<SWScreen> screens = swDefinition.getScreens();
         if(screens.size() > 0){
             SWScreen currentScreen = screens.get(showPage);
+            currentWizardPage = showPage;
             // show/hide prev/next buttons if we are at the beninning/end
             if(showPage == screens.size() - 1) {
                 ((Button) findViewById(R.id.next_button)).setVisibility(View.GONE);

app/src/main/res/layout/activity_setupwizard.xml

@@ -31,6 +31,7 @@
             android:id="@+id/fullscreen_content_fields"
             android:layout_width="match_parent"
             android:layout_height="match_parent"
+            android:gravity="center_vertical|center_horizontal"
             android:orientation="vertical">
 
         </LinearLayout>