Search contacts now update when there are changes to the cp2 db.

Since we close the original cursor we queried in the cursor loader,
we need to assign a new content observer to the cursor we build so
that our search results update when there are changes to the contacts
db.

Bug: 63830179
Test: manual
PiperOrigin-RevId: 177368459
Change-Id: I025ea70334265cb2fdc651ed7ea046b039738e94