Settings: Add SMS Mirroring.

Bug: 37546615

Test: Updated Robolectric suite with new unit tests.

Change-Id: I02e1723e1b125b004ff679d6242df14bca4f08ce

res/drawable/ic_compare_arrows_24dp.xml

@@ -0,0 +1,26 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- 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.
+-->
+
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+        android:width="24dp"
+        android:height="24dp"
+        android:viewportWidth="24.0"
+        android:viewportHeight="24.0"
+        android:tint="?android:attr/colorControlNormal">
+    <path
+        android:fillColor="#FF000000"
+        android:pathData="M9.01,14L2,14v2h7.01v3L13,15l-3.99,-4v3zM14.99,13v-3L22,10L22,8h-7.01L14.99,5L11,9l3.99,4z"/>
+</vector>