Handle case where profiles.xml was partially saved

If profiles.xml is only partially written out to disk when the device
reboots, it's possible for the parsing to end up in an endless loop
since we are not checking for XmlPullParser.END_DOCUMENT events.  This
patch adds checks for those events and throws an IOException.

Change-Id: I417774dd67053e73ba9a5a418d914aad22fe3c24