Updated SWE Browser "About" menu item

- Changed "About" menu to preference screen layout,
  instead of popup
- Added Version, Build date, Build Hash, User Agent, Help
  and Feedback

Change-Id: I2c5b8f74f9ffc945adb305042c1ebcd61283e047
diff --git a/src/com/android/browser/PreferenceKeys.java b/src/com/android/browser/PreferenceKeys.java
index f3e752f..ea6b1d6 100644
--- a/src/com/android/browser/PreferenceKeys.java
+++ b/src/com/android/browser/PreferenceKeys.java
@@ -121,4 +121,15 @@
      * Key for whether or not the last run was paused.
      */
     static final String KEY_LAST_RUN_PAUSED = "last_paused";
+
+    // ----------------------
+    // Keys for about_preferences.xml
+    // ----------------------
+    static final String PREF_ABOUT = "about";
+    static final String PREF_VERSION = "version";
+    static final String PREF_BUILD_DATE = "built";
+    static final String PREF_BUILD_HASH = "hash";
+    static final String PREF_USER_AGENT = "user_agent";
+    static final String PREF_HELP = "help_about";
+    static final String PREF_FEEDBACK = "feedback";
 }