Implements a ping listener from XEP-0199 XMPP ping.
In the future, we can send an XMPP ping to the server to check for the state
of the connection.
<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android">
<rotate android:fromDegrees="0" android:toDegrees="360"
android:pivotX="50%" android:pivotY="50%"
android:duration="5000"
android:repeatMode="restart"
android:repeatCount="infinite" />
</set>