Introduce config_show_wallpaper_attribution.

This introduces a boolean flag in which when set to true, Wallpaper
Attribution will be shown in the Legal page. When set to false, it
will be hidden. Wallpaper has always been removed from search results,
so that has not changed.

Bug: 62378616
Test: make RunSettingsRoboTests ROBOTEST_FILTER=LegalSettings passes.
Change-Id: Ia6f3e7d1ef471eecf79f1b46616fa4ba27d35748

tests/robotests/src/com/android/settings/LegalSettingsTest.java

@@ -15,23 +15,49 @@
  */
 package com.android.settings;
 
+import static com.google.common.truth.Truth.assertThat;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.spy;
+
 import android.content.Context;
 
 import com.android.settings.testutils.SettingsRobolectricTestRunner;
 import com.android.settings.testutils.XmlTestUtils;
+
+import org.junit.Before;
 import org.junit.Test;
 import org.junit.runner.RunWith;
+import org.mockito.MockitoAnnotations;
 import org.robolectric.RuntimeEnvironment;
 import org.robolectric.annotation.Config;
 
 import java.util.List;
 
-import static com.google.common.truth.Truth.assertThat;
-
 @RunWith(SettingsRobolectricTestRunner.class)
 @Config(manifest = TestConfig.MANIFEST_PATH, sdk = TestConfig.SDK_VERSION)
 public class LegalSettingsTest {
 
+    private Context mContext;
+    private LegalSettings mFragment;
+    private boolean mWallpaperRemoved;
+
+    @Before
+    public void setUp() {
+        MockitoAnnotations.initMocks(this);
+        mContext = spy(RuntimeEnvironment.application);
+        mFragment = new LegalSettings() {
+            @Override
+            protected boolean removePreference(String key) {
+                if (LegalSettings.KEY_WALLPAPER_ATTRIBUTIONS.equals(key)) {
+                    mWallpaperRemoved = true;
+
+                    return true;
+                }
+                return false;
+            }
+        };
+    }
+
     @Test
     public void testNonIndexableKeys_existInXmlLayout() {
         final Context context = RuntimeEnvironment.application;
@@ -43,4 +69,19 @@ public class LegalSettingsTest {
 
         assertThat(keys).containsAllIn(niks);
     }
-}
+
+    @Test
+    public void testWallpaperAttributions_byDefault_shouldBeShown() {
+        mFragment.checkWallpaperAttributionAvailability(mContext);
+
+        assertThat(mWallpaperRemoved).isEqualTo(false);
+    }
+
+    @Test
+    @Config(qualifiers = "mcc999")
+    public void testWallpaperAttributions_ifDisabled_shouldNotBeShown() {
+        mFragment.checkWallpaperAttributionAvailability(mContext);
+
+        assertThat(mWallpaperRemoved).isEqualTo(true);
+    }
+}