gitlab-ci: only run Espresso tests on emulators newer than 25

app/src/androidTest/java/org/fdroid/fdroid/MainActivityEspressoTest.java

@@ -49,6 +49,7 @@ import static org.hamcrest.Matchers.not;
 import static org.junit.Assert.assertTrue;
 import static org.junit.Assume.assumeTrue;
 
+@LargeTest
 @RunWith(AndroidJUnit4.class)
 public class MainActivityEspressoTest {
     public static final String TAG = "MainActivityEspressoTest";