Add sleep time to start TestActivity

import com.android.internal.infra.AndroidFuture;

import com.google.common.util.concurrent.Uninterruptibles;

import org.junit.After;

import org.junit.Before;

import org.junit.Test;

import org.junit.runner.RunWith;

import java.time.Duration;

import java.util.concurrent.TimeUnit;

/**

@Presubmit

public class GameSessionTrampolineActivityTest {

    private static final Duration TEST_ACTIVITY_OPEN_DURATION = Duration.ofSeconds(5);

    @Before

    public void setUp() {

        setAlwaysFinishActivities(false);

            startTestActivityViaGameSessionTrampolineActivity() {

        Intent testActivityIntent = new Intent();

        testActivityIntent.setClass(getInstrumentation().getTargetContext(), TestActivity.class);

        sleep(TEST_ACTIVITY_OPEN_DURATION);

        return startGameSessionTrampolineActivity(testActivityIntent);

    }

    private static void sleep(Duration sleepDuration) {

        Uninterruptibles.sleepUninterruptibly(sleepDuration.toMillis(), TimeUnit.MILLISECONDS);

    }

    private static AndroidFuture<GameSessionActivityResult> startGameSessionTrampolineActivity(

            Intent targetIntent) {

        AndroidFuture<GameSessionActivityResult> resultFuture = new AndroidFuture<>();