title: Async task gets UI stuck
body: <p>I have 2 async tasks (which does server requests) running just before i leave my activity.
  sometimes the activity which runs this async tasks gets stuck until the async tasks finish, and sometimes the next activity shows and gets stuck until the async tasks finishes.</p>
  
  <p>my question is how do i run this task in a way in which my activity's UI doesn't gets stuck (the UI is not dependable on the responses in the async tasks)</p>