CDD: Require support for hardware-backed key attestation

- Attestation will provide a way for developers to verify off-device
that a particular key has the expected security properties.
- This is important for trustworthy security designs for particularly
sensitive applications, e.g. payment & banking.

Bug:33676518, 30974815
Change-Id: I92c39b69e26a7c7cd8c32dd4689de52b0cc8f1f0
1 file changed