title: How to work with back button in Android emulator
body: <p>I have 3 to 4 activities. It moves from 1 activity to another. If I am in 2nd activity then after pressing the back button of emulator it should be open the 1st activity. It opens also
  but problem is both activities are connected to database. If in one activity any changes occur then it should appear in other activities.</p>
  
  <p>So what to do here so that refresh of activity can be done in back button also?</p>