Secretkeeper: use Ed25519 identity key

Test: VtsSecretkeeperTargetTest
Change-Id: I27aebb8913c34f043b7ccc7b6e23969377313e1e
diff --git a/security/secretkeeper/default/Android.bp b/security/secretkeeper/default/Android.bp
index 1d75c74..d8ccb63 100644
--- a/security/secretkeeper/default/Android.bp
+++ b/security/secretkeeper/default/Android.bp
@@ -34,6 +34,7 @@
         "libauthgraph_core",
         "libauthgraph_hal",
         "libbinder_rs",
+        "libcoset",
         "liblog_rust",
         "libsecretkeeper_core_nostd",
         "libsecretkeeper_comm_nostd",