CDD: Require checking the primary authentication periodically

- Added this requirement for the following reasons:
- Security; The supplemental unlocks are less secure than the primary
credential so limit the risk by periodically asking for the main
password.
- Usability; Make sure the user enters their primary knowledge factor
often enough not to forget it.

Bug: 38314942
Change-Id: I664813f58f5881c51500559eb7175fd759885d9e
1 file changed