Build the gRPC Java Authentication library

Add a Soong module to build the gRPC authentication library from source.

Test: m grpc-java-auth grpc-java
Bug: 148404241
Change-Id: I8afdf8c14773de4c13889016b0bfd8b6da132548
diff --git a/Android.bp b/Android.bp
index f7835ef..37c6c8f 100644
--- a/Android.bp
+++ b/Android.bp
@@ -17,6 +17,7 @@
 java_library_host {
     name: "grpc-java",
     static_libs: [
+        "grpc-java-auth",
         "grpc-java-context",
         "grpc-java-core",
         "grpc-java-core-inprocess",
diff --git a/auth/Android.bp b/auth/Android.bp
new file mode 100644
index 0000000..68d08f4
--- /dev/null
+++ b/auth/Android.bp
@@ -0,0 +1,27 @@
+// Copyright (C) 2020 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.
+//
+
+java_library_host {
+    name: "grpc-java-auth",
+    srcs: [
+        "src/main/java/io/grpc/auth/*.java",
+    ],
+    libs: [
+        "grpc-java-core",
+        "google-auth-library-credentials-0.13.0",
+        "guava",
+        "jsr305",
+    ],
+}