Fix keyguard listview widgets for secondary users

This fixes a bug where secondary user widgets weren't being updated
properly because the system was checking for SYSTEM_UID which no
longer works with keyguard in a separate process.  The symptom was an
app with a listview, like Gmail, would always show an empty list for
secondary users.

Change-Id: I3749a7a0b39f1eb7922966af0fbdcefdd804e41e