Change default preload setting to 'Always'.

Also some tidying up to that the default is only specified in a
single place.

Change-Id: I6d66739a8b0d307f8af3c29c62d122a3044c4943
diff --git a/src/com/android/browser/BrowserSettings.java b/src/com/android/browser/BrowserSettings.java
index ce8a9c1..6b8daec 100644
--- a/src/com/android/browser/BrowserSettings.java
+++ b/src/com/android/browser/BrowserSettings.java
@@ -789,7 +789,7 @@
     }
 
     private String getDefaultPreloadSetting() {
-        return getPreloadOnWifiOnlyPreferenceString(mContext);
+        return mContext.getResources().getString(R.string.pref_data_preload_default_value);
     }
 
     public String getPreloadEnabled() {