Only default APN type can make preference selectable.

- Current design is only to check mms type, but if there are other APN
 types group in one apn settings, it will show the radio button and the
 user can see the radio button and select it.

 - Improvement: Only make APN setting with defalut APN type be able to be selected.
    - https://screenshot.googleplex.com/8pfQinjya2NJWoV
Bug: 180475805
Test: Maunal test with ATT SIM.
Change-Id: Ic14121d7ce2a53b0f883a0637fc390c2aa4dd1d7
Merged-In: Iae6943971c0cc6d31dc0e9d4dd97e850117adbfd

src/com/android/settings/network/ApnSettings.java

@@ -342,7 +342,7 @@ public class ApnSettings extends RestrictedSettingsFragment
                     pref.setSummary(apn);
                 }
 
-                final boolean selectable = ((type == null) || !type.equals("mms"));
+                final boolean selectable = ((type == null) || type.contains("default"));
                 pref.setSelectable(selectable);
                 if (selectable) {
                     if ((mSelectedKey != null) && mSelectedKey.equals(key)) {