[Android] Add an out-of-app instrumentation driver APK.

testing/android/reporter/BUILD.gn

+# Copyright 2015 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+import("//build/config/android/rules.gni")
+
+# GYP: //testing/android/on_device_instrumentation.gyp:reporter_java
+android_library("reporter_java") {
+  chromium_code = true
+
+  deps = [
+    "//base:base_java",
+  ]
+  java_files = [
+    "java/src/org/chromium/test/reporter/TestStatusListener.java",
+    "java/src/org/chromium/test/reporter/TestStatusReceiver.java",
+    "java/src/org/chromium/test/reporter/TestStatusReporter.java",
+  ]
+}