Add test size annotation.

Rational/Background:

@MediumTest: An integration or functional test that validates the
interaction of one or more application modules on a single machine.
(should run under 1 sec: Usually get killed after 5 min)
@LargeTest: A system test, integration test, or end-to-end test that
verifies that a complete application works and accounts for the behavior
of external subsystems.
(Usually get killed after 15 min)

Change-Id: I8b668af3d2ca09c43ad45c6fd72b1d0d80c6b7d3

tests/src/com/android/launcher3/model/GridSizeMigrationTaskTest.java

@@ -5,6 +5,7 @@ import android.content.Intent;
 import android.database.Cursor;
 import android.graphics.Point;
 import android.test.ProviderTestCase2;
+import android.test.suitebuilder.annotation.MediumTest;
 
 import com.android.launcher3.InvariantDeviceProfile;
 import com.android.launcher3.LauncherModel;
@@ -19,6 +20,7 @@ import java.util.HashSet;
 /**
  * Unit tests for {@link GridSizeMigrationTask}
  */
+@MediumTest
 public class GridSizeMigrationTaskTest extends ProviderTestCase2<TestLauncherProvider> {
 
     private static final long DESKTOP = LauncherSettings.Favorites.CONTAINER_DESKTOP;