[phone] Don't start search loader before it's ready

The setFilter() call in Dialtacs.onStart() indirectly started the loader,
but at this point the initialization in ContactEntryListFragment.onStart()
hasn't done yet, so we shouldn't the loader yet.

This caused the first loader to start with the wrong sort order if you have
"sort by last name" set.

Bug 5252597

Change-Id: Ia1efc7b097cb5c1068f0b2ebb6d61fb0c29f4302