Factor keystore_attestation_id into library and also use this in credstore.

This was needed because credstore needs to generate and pass the
generated AttestationApplicationId to the Identity Credential HAL.

Bug: 111446262
Test: atest android.security.identity.cts
Test: VtsHalIdentityCredentialTargetTest
Test: android.hardware.identity-support-lib-test
Change-Id: Id22b85ca083e23c7e1fbd3459910fba37a5db137
8 files changed