title: Add login Activity afterwards
body: <p>I started my android app by making a <code>ListViewActivity</code>.</p>
  
  <p>Now I decided to make a <code>LogInScreenActivity</code>. Do i have to declare the <code>LogInScreenActivity</code> as <code>MainActivity</code>?</p>
  
  <p>Or can i change the <code>MainActivity</code> manually? I'm using Android Studio and new ad Androidl</p>