BACKPORT: Disable changing lock when device is not provisioned.

When the device is not yet provisioned and settings is launched:
- disable the entry point for changing device lock
- remove the search panel from settings home page
- remove the search menu

Bug: 110034419
Test: make RunSettingsRoboTests
Change-Id: Ieb7eb0e8699229ec0824ccc19d7b958ac44965a2
Merged-In: Ieb7eb0e8699229ec0824ccc19d7b958ac44965a2
(cherry picked from commit 770f4abf)
CVE-2018-9501