bufferstreams: Add AIDL interfaces/parcelables for stream types

These interfaces incorporate jreck@'s ideas for caching and
BufferAttachements. This means that we only need to send the
heavy-weight HardwareBuffers once, and then we can just send a
lightweight reference to the buffer.

This interface is not intended for public use yet and is going to be
actively developed for the next few months.

Bug: 296099728
Bug: 296450069
Test: builds
Change-Id: I6ca17dda1186ae74773bc344f3cda4b5574585aa
diff --git a/libs/bufferstreams/aidl/Android.bp b/libs/bufferstreams/aidl/Android.bp
new file mode 100644
index 0000000..3f1fa4e
--- /dev/null
+++ b/libs/bufferstreams/aidl/Android.bp
@@ -0,0 +1,43 @@
+// Copyright (C) 2024 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.
+
+aidl_interface {
+    name: "android.graphics.bufferstreams",
+    unstable: true,
+    flags: ["-Werror"],
+    srcs: ["android/graphics/bufferstreams/*.aidl"],
+    headers: [
+        "HardwareBuffer_aidl",
+    ],
+    imports: [
+        "android.hardware.common-V2",
+    ],
+    backend: {
+        cpp: {
+            enabled: false,
+        },
+        java: {
+            enabled: false,
+        },
+        ndk: {
+            enabled: false,
+        },
+        rust: {
+            enabled: true,
+            additional_rustlibs: [
+                "libnativewindow_rs",
+            ],
+        },
+    },
+}