Revert "Skip main user designation/creation when booting to HSU on provisioned devices."

This reverts commit 201a8feb.

Reason for revert: need a different approach
(commit 869f7863c340a383f07f58baf09f8cfebffa4214)

Bug: 374926694
Bug: 443085470
Test: yes, tested
Flag: EXEMPT revert

Change-Id: I31d5f2f892c70ecd2227ea4fe17cdca097dc7e9a