InitialLockSetupHelper: fix chars <=> bytes conversion am: d890ee393b am: d4969d6e72 am: 899c141878 am: 0f806a3506

Original change: https://android-review.googlesource.com/c/platform/frameworks/opt/car/setupwizard/+/2700613

Change-Id: I99e808d049332b3341d5ca5793abc7dee654a23f
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>