MVNO value is not grayed out when MVNO type is none

MVNO type is judged as none by comparing key string to "None",
but this logic does not work when language setting is non English
because key is not "None" due to translation.

Bug: 27267663
Change-Id: Ic39a084cd77f661f833b13106dc28444926487d8

src/com/android/settings/ApnEditor.java

@@ -453,11 +453,7 @@ public class ApnEditor extends InstrumentedPreferenceActivity
             return null;
         } else {
             String[] values = mRes.getStringArray(R.array.mvno_type_entries);
-            if (values[mvnoIndex].equals("None")) {
-                mMvnoMatchData.setEnabled(false);
-            } else {
-                mMvnoMatchData.setEnabled(true);
-            }
+            mMvnoMatchData.setEnabled(mvnoIndex != 0);
             if (newValue != null && newValue.equals(oldValue) == false) {
                 if (values[mvnoIndex].equals("SPN")) {
                     mMvnoMatchData.setText(mTelephonyManager.getSimOperatorName());