title: Android from Fragment to Activity, back press dont go back to fragemt
body: <p>I am loading an activity from my fragment. If I press the back button on the device, it goes back to the Gridfragment (as expected). </p>
  
  <blockquote>
    <blockquote>
      <p>But, if I click the action bar back arrow, it goes back to the mainActivity hosted fragment = <strong>HomeFragment</strong> and not the <strong>Gridfragment</strong>.</p>
    </blockquote>
  </blockquote>
  
  <p>From HomeFragment - ( default fragment) </p>
  
  <pre><code>Fragment f = GridFragment.newInstance(GridFragment.TAG_bundlePhotosList);
  getSupportFragmentManager().beginTransaction().replace(R.id.fragment_container, f).addToBackStack(null).commit();
  </code></pre>
  
  <p>Fragment Grid:</p>
  
  <pre><code>Intent i = new Intent(getActivity(), ImagePreviewActivity.class);
  i.putExtra("from_grid", "from_grid");
  tartActivity(i);
  </code></pre>
  
  <p>ImagePreviewActivity :</p>
  
  <pre><code>//Display back arrow
  getSupportActionBar().setDisplayHomeAsUpEnabled(true);
  getSupportActionBar().setTitle(ImagePreviewActivity);
  </code></pre>