Remove IMS from editabe APNs

If APN type is not specified, it will default to all APN types.
Remove IMS from editable APN types to prevent both default and IMS on
the same connection.

Test: make RunSettingsRoboTests
Bug: 195105491
Change-Id: I0db32412e8a2948509f235c94e1d681001b79995

src/com/android/settings/network/apn/ApnEditor.java

@@ -1256,7 +1256,8 @@ public class ApnEditor extends SettingsPreferenceFragment
             if (!readOnlyApnTypes.contains(apnType)
                     && !apnType.equals(APN_TYPE_IA)
                     && !apnType.equals(APN_TYPE_EMERGENCY)
-                    && !apnType.equals(APN_TYPE_MCX)) {
+                    && !apnType.equals(APN_TYPE_MCX)
+                    && !apnType.equals(APN_TYPE_IMS)) {
                 if (first) {
                     first = false;
                 } else {