Fix the null URI versus "null" versus Json.NULL

Change-Id: I51d3683d6c0f637689aded58bba95fdec9dbe8ce
diff --git a/src/com/android/mail/providers/UIProvider.java b/src/com/android/mail/providers/UIProvider.java
index 5f2d865..4bf7f02 100644
--- a/src/com/android/mail/providers/UIProvider.java
+++ b/src/com/android/mail/providers/UIProvider.java
@@ -209,6 +209,12 @@
         public static final String NAME = "name";
 
         /**
+         * This integer contains the type of the account: Google versus non google. This is not
+         * returned by the UIProvider, rather this is a notion in the system.
+         */
+        public static final String TYPE = "type";
+
+        /**
          * This integer column returns the version of the UI provider schema from which this
          * account provider will return results.
          */