Add AIDL for LayerMetadtaKey

to share the same definition between C++ and Java code

Bug: 143912669
Test: make
Change-Id: I7f2a189f134f1f924906a22dfc30ccf221cfd2d7
diff --git a/aidl/gui/android/view/LayerMetadataKey.aidl b/aidl/gui/android/view/LayerMetadataKey.aidl
new file mode 100644
index 0000000..7026ca8
--- /dev/null
+++ b/aidl/gui/android/view/LayerMetadataKey.aidl
@@ -0,0 +1,26 @@
+/*
+ * Copyright (C) 2019 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 android.view;
+
+/** @hide */
+@Backing(type="int")
+enum LayerMetadataKey {
+    METADATA_OWNER_UID = 1,
+    METADATA_WINDOW_TYPE = 2,
+    METADATA_TASK_ID = 3,
+    METADATA_MOUSE_CURSOR = 4,
+}