title: Cannot open custom file extension
body: <p>I have a file format I wish to support, it's just a zip but I've renamed it .amg so my app can read it. </p>
  
  <p>On my samsung phone with gingerbread it works fine and it opens.</p>
  
  <p>On my motorola phone with kitkat all I get is can not open it.</p>
  
  <p>I've tried various solutions found here but none seem to work.</p>
  
  <p>Typically I copy the file into the download folder on the phone and click the file.</p>
  
  <p>The only thing that works on kitkat is if I open the file using Astro File Manager, but I can't force that app on people. So what's wrong that makes Astro work but nothing else?</p>
  
  <pre><code>    &lt;activity
          android:name="com.test.StartupActivity"
          android:label="@string/app_name"
          android:theme="@style/backdropTheme" &gt;
          &lt;intent-filter&gt;
              &lt;action android:name="android.intent.action.MAIN" /&gt;
  
              &lt;category android:name="android.intent.category.LAUNCHER" /&gt;
          &lt;/intent-filter&gt;
          &lt;intent-filter&gt;
              &lt;action android:name="android.intent.action.VIEW" /&gt;
              &lt;category android:name="android.intent.category.DEFAULT" /&gt;
              &lt;data android:host="*" /&gt;
              &lt;data android:mimeType="*/*" /&gt;
              &lt;data android:scheme="file" /&gt;
              &lt;data android:pathPattern=".*\\.amg" /&gt;
          &lt;/intent-filter&gt;
      &lt;/activity&gt;
  </code></pre>
  
  <p><em><strong></em>**</strong> [EDIT] <strong><em>*</em>**<em>*</em>**</strong>
  If I use Astro file manager in kitkat it seems to work. So Astro works, the three other ones I've tried including built in one doesn't but with gingerbread it always works. </p>
  
  <p>However, on my kitkat when I try and open the file I get the following exception:
  invalid stored block lengths.</p>