Add calculatePreferredNetworkType to PhoneInterfaceManager.

Bug: b/14134668
Change-Id: Iba7dcd50c1ba84b634eed53030456a2f84af6e3c
diff --git a/src/com/android/phone/PhoneInterfaceManager.java b/src/com/android/phone/PhoneInterfaceManager.java
index 7f75ab2..7692a6b 100644
--- a/src/com/android/phone/PhoneInterfaceManager.java
+++ b/src/com/android/phone/PhoneInterfaceManager.java
@@ -1554,6 +1554,18 @@
     }
 
     /**
+     * Get the calculated preferred network type.
+     * Used for debugging incorrect network type.
+     *
+     * @return the preferred network type, defined in RILConstants.java.
+     */
+    @Override
+    public int getCalculatedPreferredNetworkType() {
+        enforceReadPermission();
+        return PhoneFactory.calculatePreferredNetworkType(mPhone.getContext());
+    }
+
+    /**
      * Get the preferred network type.
      * Used for device configuration by some CDMA operators.
      *