Add carrier settings version to network details page

This adds a preference showing the carrier settings version to the
mobile network details page.

Bug: 123995414
Test: make RunSettingsRoboTests
Change-Id: I7b80ead0eadb7375b4404262337e47f75102125c

src/com/android/settings/network/telephony/CarrierSettingsVersionPreferenceController.java

@@ -0,0 +1,54 @@
+/*
+ * Copyright (C) 2019 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.settings.network.telephony;
+
+import android.content.Context;
+import android.os.PersistableBundle;
+import android.telephony.CarrierConfigManager;
+import android.telephony.SubscriptionManager;
+
+import com.android.settings.core.BasePreferenceController;
+
+public class CarrierSettingsVersionPreferenceController extends BasePreferenceController {
+
+    private int mSubscriptionId;
+    private CarrierConfigManager mManager;
+
+    public CarrierSettingsVersionPreferenceController(Context context, String preferenceKey) {
+        super(context, preferenceKey);
+        mManager = context.getSystemService(CarrierConfigManager.class);
+        mSubscriptionId = SubscriptionManager.INVALID_SUBSCRIPTION_ID;
+    }
+
+    public void init(int subscriptionId) {
+        mSubscriptionId = subscriptionId;
+    }
+
+    @Override
+    public CharSequence getSummary() {
+        final PersistableBundle config = mManager.getConfigForSubId(mSubscriptionId);
+        if (config == null) {
+            return null;
+        }
+        return config.getString(CarrierConfigManager.KEY_CARRIER_CONFIG_VERSION_STRING);
+    }
+
+    @Override
+    public int getAvailabilityStatus() {
+        return AVAILABLE;
+    }
+}