Regenerate CE key for non-system users when needed

Try to be more robust in the case where the device is rebooted during
the first boot, in between the generation and the storage of the CE key
for a user other than user 0.  This is relevant when users are created
during early boot, which Automotive devices do.

Bug: 232452368
Bug: 251213447
Ignore-AOSP-First: depends on other changes in internal master
Change-Id: Ic8f19a36c1385a71a168a330e87675433925a60f
1 file changed