Update cts to not require multi-user when managed_users are declared

Tests that need to create a managed profile do not need to check
multi-user support.
Also remove the cts test which checks that multi-user support is
a prerequisite for managed_users.

BUG: 21119929

Change-Id: Ie58cf9adc675318d810dcb48beeb5b4842b557c4
2 files changed