Use userHandle not credentialOwnerUserId to check if it needs to show lock

It is possible that unified keys stored in keystore is not migrated,
while work mode is off and upgrade happens.
At this moment, user not able to turn on work mode as work is not unlocked,
and user cannot unlock work as parent's has a challenge.
mLockPatternUtils.isSecure(userHandle) should be the same as
mLockPatternUtils.isSecure(credentialOwnerUserId), except it is a unified
lock and work profile does not setup a lock/key in keystore yet(migration).

Bug: 28689675
Change-Id: Ia0755caa10ff94a25cf26c3e5907ecd33abd866e