title: BackButton calls previous activity
body: <p>Use of this code I call Next Activity.</p>
  
  <p><strong>Code</strong></p>
  
  <pre><code>public void click_contact(View v)
  {
   Intent myIntent = new Intent(MainActivity.this, ContactActivity.class);
   MainActivity.this.startActivity(myIntent);
   overridePendingTransition (R.anim.slide_in_right, R.anim.slide_out_left);
   finish();
  }
  </code></pre>
  
  <p>So 'ContactActivity' is lunched.
  when the built-in "back" button from my device is pressed,the previous activity ('MainActivity') is closed.
  But I want relaunch this activity.</p>