Create test utils and shims for porting AppSearch CTS tests.

The shims adapt the framework API to ListenableFuture so that the
jetpack tests can be reused.

Bug: 170997047
Bug: 162450968
Bug: 175661706
Test: CtsAppSearchTestCases
Change-Id: I649a94b784fb74af137788e3a08106296dcb57fb
diff --git a/apex/appsearch/testing/Android.bp b/apex/appsearch/testing/Android.bp
new file mode 100644
index 0000000..f742ffc
--- /dev/null
+++ b/apex/appsearch/testing/Android.bp
@@ -0,0 +1,24 @@
+// 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 {
+    name: "AppSearchTestUtils",
+    srcs: ["java/**/*.java"],
+    libs: [
+        "androidx.test.ext.junit",
+        "framework",
+        "framework-appsearch",
+        "guava",
+        "truth-prebuilt",
+    ],
+}