CDD: Add per-user block-level encryption to storage encryption

Add an alternative section to define encryption requirements for
device implementations using per-user block-level encrypted
partition.

Bug: 184198954
Test: none
Change-Id: Icba5a5541c367f8863466b453e249800c1f6d9aa
(cherry picked from commit 2ea5b7f402881b48dcd02acbc12d1fc2348adb18)
1 file changed