title: Activity-Alias gets removed on app update
body: <p>I have implemented two <code>activity-alias</code> that the user should be able to enable or disable in runtime.</p>
  
  <pre><code>&lt;activity-alias
      android:name=".ui.alias.open_location"
      android:targetActivity=".ui.activity.location"
      android:enabled="false"&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;/activity-alias&gt;
  </code></pre>
  
  <p>I do not want them to be enabled in the beginning, to not clutter up the app-screen of the users device. But in runtime, the user should be able to enable the alias. I do this via the <code>PackageManager</code>:</p>
  
  <pre><code>PackageManager pm  = getApplicationContext().getPackageManager();
  ComponentName componentName = new ComponentName(context, ".ui.alias.open_location");
  pm.setComponentEnabledSetting(componentName,
                                PackageManager.COMPONENT_ENABLED_STATE_ENABLED,
                                PackageManager.DONT_KILL_APP);
  </code></pre>
  
  <p>This works like charm in the beginning, but the alias gets disabled again, when an update of my app is installed. How can I prevent the system from overwriting the enabled state by the manifest? I don't want the user to floot with Launcher in the beginning and I don't want the user to recreate all alias shortcuts after an update.</p>
  
  <p>I think I would need something similar to <code>PackageManager.COMPONENT_ENABLED_STATE_DISABLED_USER</code>, but only for enabled state.</p>
  
  <p>Thanks!</p>