Micro cleanup and refactoring

- organize import
- remove unused code in ContextualCardLoaderTest
- refactor CardDatabaseHelper

Test: robotest
Change-Id: I1a5a49bee1c4edb34f1c59f3dbe37cb22f01b0d4

src/com/android/settings/DateTimeSettings.java

@@ -20,7 +20,6 @@ import android.app.Activity;
 import android.app.Dialog;
 import android.content.Context;
 import android.content.Intent;
-import android.os.UserManager;
 import android.provider.SearchIndexableResource;
 
 import com.android.internal.logging.nano.MetricsProto.MetricsEvent;

src/com/android/settings/homepage/contextualcards/CardDatabaseHelper.java

@@ -197,12 +197,11 @@ public class CardDatabaseHelper extends SQLiteOpenHelper {
     }
 
     Cursor getContextualCards() {
-        final SQLiteDatabase db = this.getReadableDatabase();
+        final SQLiteDatabase db = getReadableDatabase();
         final String selection = CardColumns.CARD_DISMISSED + "=0";
-        Cursor cursor = db.query(CARD_TABLE, null /* columns */, selection,
+        return db.query(CARD_TABLE, null /* columns */, selection,
                 null /* selectionArgs */, null /* groupBy */, null /* having */,
                 CardColumns.SCORE + " DESC" /* orderBy */);
-        return cursor;
     }
 
     /**

tests/robotests/src/com/android/settings/homepage/contextualcards/ContextualCardLoaderTest.java

@@ -28,33 +28,27 @@ import android.content.Context;
 import android.net.Uri;
 
 import com.android.settings.slices.CustomSliceRegistry;
-import com.android.settings.slices.SettingsSliceProvider;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.stream.Collectors;
 
 import org.junit.Before;
 import org.junit.Test;
 import org.junit.runner.RunWith;
 import org.robolectric.RobolectricTestRunner;
 import org.robolectric.RuntimeEnvironment;
-import org.robolectric.shadows.ShadowContentResolver;
-
-import java.util.ArrayList;
-import java.util.List;
-import java.util.stream.Collectors;
 
 @RunWith(RobolectricTestRunner.class)
 public class ContextualCardLoaderTest {
 
     private Context mContext;
     private ContextualCardLoader mContextualCardLoader;
-    private SettingsSliceProvider mProvider;
 
     @Before
     public void setUp() {
         mContext = RuntimeEnvironment.application;
         mContextualCardLoader = spy(new ContextualCardLoader(mContext));
-        mProvider = new SettingsSliceProvider();
-        ShadowContentResolver.registerProviderInternal(SettingsSliceProvider.SLICE_AUTHORITY,
-                mProvider);
     }
 
     @Test