Android Studio Splash Screen Test - java.lang.RuntimeException: Can't create handler inside thread that has not called Looper.prepare()

Question

I've created a splash screen in my app that displays for 3 seconds before moving to LogInActivity. It looks like this:

public class SplashScreenActivity extends AppCompatActivity {

//  Splash screen displays for 3 seconds.
    private static int SplashTimer = 3000;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_splash_screen);

        getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,WindowManager.LayoutParams.FLAG_FULLSCREEN);

        finishTiming();

    }

    public void finishTiming() {
        Handler h = new Handler(Looper.getMainLooper());
        h.postDelayed(new Runnable() {
            @Override
            public void run() {
                //              App then transitions to login activity.
                Intent intent = new Intent(SplashScreenActivity.this, LogInActivity.class);
                startActivity(intent);
                finish();
            }
        }, SplashTimer);
    }
}

Now I'm trying to test it and I have two tests. testTimer() checks that the timer works as it should and SplashScreenToLogin() checks that the activity moves to the LogInActivity next:

@RunWith(AndroidJUnit4.class)
public class SplashScreenActivityInstrumentationTest {

    SplashScreenActivity splashScreenActivity;
    private Instrumentation.ActivityMonitor activityMonitor;

    @Before
    public void createSplashScreenActivity() {

        splashScreenActivity = new SplashScreenActivity();
        activityMonitor = InstrumentationRegistry.getInstrumentation().addMonitor(LogInActivity.class.getName(), null, false);
    }

    @Test
    public void testTimer() {
        assertFalse(splashScreenActivity.isFinishing());

        splashScreenActivity.finishTiming();
        ShadowLooper.runUiThreadTasksIncludingDelayedTasks();

        assertTrue(splashScreenActivity.isFinishing());
    }

    @Test
    public void SplashScreenToLogin() {
        splashScreenActivity.finishTiming();

        splashScreenActivity.runOnUiThread(new Runnable() {
            @Override
            public void run() {
            }
        });

        LogInActivity logInActivity = (LogInActivity) InstrumentationRegistry.getInstrumentation().waitForMonitorWithTimeout(activityMonitor, 10000);
        assertNotNull(logInActivity);
        logInActivity.finish();

    }
}

My issues is that when I run this I get the following error: java.lang.RuntimeException: Can't create handler inside thread that has not called Looper.prepare()

This error displays at the first line of each test function and I'm not sure why. Can someone explain why it's happening and a potential solution?