Improve notification slice string on home page

Add ContextualNotificationChannelSlice to show more clear sub title on
notification slice.

Fixes: 128641319
Test: visual, robotests
Change-Id: I650102f4cde7d8d397c7a501ba9ee76c401ba9db

tests/robotests/src/com/android/settings/homepage/contextualcards/slices/ContextualNotificationChannelSliceTest.java

@@ -0,0 +1,58 @@
+/*
+ * 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.homepage.contextualcards.slices;
+
+import static com.google.common.truth.Truth.assertThat;
+
+import android.content.Context;
+import android.net.Uri;
+
+import com.android.settings.R;
+import com.android.settings.slices.CustomSliceRegistry;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.robolectric.RobolectricTestRunner;
+import org.robolectric.RuntimeEnvironment;
+
+@RunWith(RobolectricTestRunner.class)
+public class ContextualNotificationChannelSliceTest {
+
+    private Context mContext;
+    private ContextualNotificationChannelSlice mNotificationChannelSlice;
+
+    @Before
+    public void setUp() {
+        mContext = RuntimeEnvironment.application;
+        mNotificationChannelSlice = new ContextualNotificationChannelSlice(mContext);
+    }
+
+    @Test
+    public void getUri_shouldBeContextualNotificationChannelSliceUri() {
+        final Uri uri = mNotificationChannelSlice.getUri();
+
+        assertThat(uri).isEqualTo(CustomSliceRegistry.CONTEXTUAL_NOTIFICATION_CHANNEL_SLICE_URI);
+    }
+
+    @Test
+    public void getSubTitle_shouldBeRecentlyInstalledApp() {
+        final CharSequence subTitle = mNotificationChannelSlice.getSubTitle("com.test.package", 0);
+
+        assertThat(subTitle).isEqualTo(mContext.getText(R.string.recently_installed_app));
+    }
+}