Build infra to inject slice to PreferenceFragment

Reuse the PreferenceController and LayoutPreference however create
specific one for slice:
1. SlicePreference: container to inject slice view
2. SlicePreferenceController: handle updates for slice

Also add styles for it with default layout.

Bug: 120803703
Test: RunSettingsRoboTests

Change-Id: I6ab083ad57117e6198dcba37702a25213da78719

tests/robotests/src/com/android/settings/slices/SlicePreferenceControllerTest.java

@@ -0,0 +1,81 @@
+/*
+ * Copyright (C) 2018 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.slices;
+
+import static com.google.common.truth.Truth.assertThat;
+
+import static org.mockito.Mockito.spy;
+import static org.mockito.Mockito.verify;
+
+import android.content.Context;
+import android.net.Uri;
+
+import androidx.lifecycle.LiveData;
+import androidx.slice.Slice;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.Mock;
+import org.mockito.MockitoAnnotations;
+import org.robolectric.RobolectricTestRunner;
+import org.robolectric.RuntimeEnvironment;
+
+@RunWith(RobolectricTestRunner.class)
+public class SlicePreferenceControllerTest {
+    private static final String KEY = "slice_preference_key";
+
+    @Mock
+    private LiveData<Slice> mLiveData;
+    private Context mContext;
+    private SlicePreferenceController mController;
+    private Uri mUri;
+
+
+    @Before
+    public void setUp() {
+        MockitoAnnotations.initMocks(this);
+
+        mContext = spy(RuntimeEnvironment.application);
+        mController = new SlicePreferenceController(mContext, KEY);
+        mController.mLiveData = mLiveData;
+        mUri = Uri.EMPTY;
+    }
+
+    @Test
+    public void isAvailable_uriNull_returnFalse() {
+        assertThat(mController.isAvailable()).isFalse();
+    }
+
+    @Test
+    public void isAvailable_uriNotNull_returnTrue() {
+        mController.setSliceUri(mUri);
+        assertThat(mController.isAvailable()).isTrue();
+    }
+
+    @Test
+    public void onStart_registerObserver() {
+        mController.onStart();
+        verify(mLiveData).observeForever(mController);
+    }
+
+    @Test
+    public void onStop_unregisterObserver() {
+        mController.onStop();
+        verify(mLiveData).removeObserver(mController);
+    }
+}