Individual attestation: Feature file

Add a file for the unique attestation feature.

Bug: 140920022
Test: That it compiles.
Change-Id: I6e4577b793d6b28bff855d74b313be7eeeab3f05
Merged-In: I6e4577b793d6b28bff855d74b313be7eeeab3f05
(cherry picked from commit 9606640a396ce74520bb17da909e622485774e5d)
1 file changed