[bssl] Implement AEAD BoringSSL wrapper

AEAD will be used to encrypt the private key in the RKP HAL.

Bug: 302286887
Test: atest libbssl_avf_nostd.test
Change-Id: I734cf5ecd8b938f2c47f439d6f51594ccafb4ff2
diff --git a/libs/bssl/src/lib.rs b/libs/bssl/src/lib.rs
index 8b38f5b..898e16c 100644
--- a/libs/bssl/src/lib.rs
+++ b/libs/bssl/src/lib.rs
@@ -18,6 +18,7 @@
 
 extern crate alloc;
 
+mod aead;
 mod cbb;
 mod digest;
 mod ec_key;
@@ -28,6 +29,7 @@
 
 pub use bssl_avf_error::{ApiName, CipherError, Error, ReasonCode, Result};
 
+pub use aead::{Aead, AeadCtx};
 pub use cbb::CbbFixed;
 pub use digest::Digester;
 pub use ec_key::{EcKey, ZVec};