Add pairing preference

This preference lives in paired category. When clicked, it will
go to the pairing page.

Bug: 35877041
Test: RunSettingsRoboTests
Change-Id: I64706c49c8d303a494d4c1827e1f86b59effd54c

src/com/android/settings/bluetooth/BluetoothPairingPreferenceController.java

@@ -0,0 +1,78 @@
+/*
+ * Copyright (C) 2017 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.bluetooth;
+
+import android.app.Fragment;
+import android.content.Context;
+import android.support.v14.preference.PreferenceFragment;
+import android.support.v7.preference.Preference;
+import android.support.v7.preference.PreferenceScreen;
+
+import com.android.settings.core.PreferenceController;
+import com.android.settings.R;
+
+
+/**
+ * Controller that shows and updates the bluetooth device name
+ */
+public class BluetoothPairingPreferenceController extends PreferenceController {
+    private static final String TAG = "BluetoothPairingPrefCtrl";
+
+    public static final String KEY_PAIRING = "pref_bt_pairing";
+    private PreferenceFragment mFragment;
+    private Preference mPreference;
+
+    public BluetoothPairingPreferenceController(Context context, PreferenceFragment fragment) {
+       super(context);
+        mFragment = fragment;
+    }
+
+    @Override
+    public boolean isAvailable() {
+        return true;
+    }
+
+    @Override
+    public String getPreferenceKey() {
+        return KEY_PAIRING;
+    }
+
+    @Override
+    public boolean handlePreferenceTreeClick(Preference preference) {
+        if (KEY_PAIRING.equals(preference.getKey())) {
+            //TODO: open the pairing page
+            return true;
+        }
+
+        return false;
+    }
+
+    /**
+     * Create pairing preference to jump to pairing page
+     *
+     * @return bluetooth preference that created in this method
+     */
+    public Preference createBluetoothPairingPreference() {
+        mPreference = new Preference(mFragment.getPreferenceScreen().getContext());
+        mPreference.setKey(KEY_PAIRING);
+        mPreference.setIcon(R.drawable.ic_add);
+        mPreference.setTitle(R.string.bluetooth_pairing_pref_title);
+
+        return mPreference;
+    }
+
+}