Enlarge texts and fit the other elements

Basically set text size to 18sp and change layouts
along with the new design.

- Add custom list item xml for Wi-Fi security field
  rename existing "custom_list_item.xml" to appropriate
  name so that we won't be confused with their naming.
- Use the custom xml just in SetupWizard.

Bug: 3364731
Change-Id: I014903277a03c359ea193dd0f0a37c84ade19fa1

src/com/android/settings/DateTimeSettingsSetupWizard.java

@@ -101,7 +101,7 @@ public class DateTimeSettingsSetupWizard extends Activity
         // mTimeZoneButton.setText(DateTimeSettings.getTimeZoneText(tz));
         mTimeZoneButton.setOnClickListener(this);
         mTimeZoneAdapter = ZonePicker.constructTimezoneAdapter(this, false,
-                R.layout.custom_list_item);
+                R.layout.date_time_setup_custom_list_item_2);
 
         final boolean autoDateTimeEnabled;
         final Intent intent = getIntent();