Introduce Secretkeeper HAL interface

Secretkeeper is a privileged component which seals the secrets of pVM
instances & releases them on successful authentication of the pVM.

The HAL should be backed by a secure TA of higher privilege than a pVM.

This patch introduces a subset of HAL spec - the SecretManagement api. The
protocol is cbor based (specified in SecretManagement.cddl).

Test: atest VtsSecretkeeperTargetTest
Bug: 293429085
Change-Id: I8e650f27d506d378a94bbc8834c68a005fb12253
diff --git a/security/secretkeeper/aidl/Android.bp b/security/secretkeeper/aidl/Android.bp
new file mode 100644
index 0000000..c77d299
--- /dev/null
+++ b/security/secretkeeper/aidl/Android.bp
@@ -0,0 +1,36 @@
+// Copyright (C) 2023 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package {
+    default_applicable_licenses: ["Android-Apache-2.0"],
+}
+
+aidl_interface {
+    name: "android.hardware.security.secretkeeper",
+    vendor_available: true,
+    srcs: ["android/hardware/security/secretkeeper/*.aidl"],
+    stability: "vintf",
+    backend: {
+        ndk: {
+            enabled: true,
+        },
+        rust: {
+            enabled: true,
+            apex_available: [
+                "//apex_available:platform",
+                "com.android.virt",
+            ],
+        },
+    },
+}