Add android build file

diff --git a/Android.bp b/Android.bp
new file mode 100644
index 0000000..5886a16
--- /dev/null
+++ b/Android.bp

@@ -0,0 +1,27 @@
+// Copyright 2018 Google LLC
+//
+// 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
+//
+//     https://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.
+
+java_library {
+  name: "ukey2",
+  proto: {
+    type: "lite",
+  },
+  srcs: [
+    "**/*.proto",
+    "**/*.java",
+  ],
+  libs: [
+    "guava",
+  ],
+}