Update Javadoc for Launcher API changes.

In ag/26226975 Some Apis in frameworks were
updated to support hidden profiles.

The flag behind those changes are now in
trunkfood full, so now we are updating the
javadoc.

Bug: 287975131
Test: atest FrameworksServicesTests
Flag: ACONFIG android.multiuser.disable_private_space_items_on_home
TRUNKFOOD

Change-Id: Ie3f5e37e3769c89d8ce4d7ca6cc915a05694de78