title: AndroidMainfest - should an intent-filter have multiple actions?
body: <p>My current intent-filter for my MainActivity looks like this</p>
  
  <pre><code>&lt;intent-filter&gt;
                  &lt;action android:name="android.intent.action.MAIN" /&gt;
                  &lt;category android:name="android.intent.category.LAUNCHER" /&gt;
                  &lt;action android:name="android.hardware.usb.action.USB_ACCESSORY_ATTACHED" /&gt;
              &lt;/intent-filter&gt;
  </code></pre>
  
  <p>Notice that there are 2 action nodes. Is this correct? Or should there only be one action node per intent-filter?</p>
  
  <p>Also, what is the purpose of the DEFAULT category?</p>
  
  <pre><code>&lt;category android:name="android.intent.category.DEFAULT" /&gt;
  </code></pre>