Add an Android sample app for Telemetry tests.

tools/android/push_apps_to_background/push_apps_to_background.gyp

Index: tools/android/push_apps_to_background/push_apps_to_background.gyp
diff --git a/tools/android/push_apps_to_background/push_apps_to_background.gyp b/tools/android/push_apps_to_background/push_apps_to_background.gyp
new file mode 100644
index 0000000000000000000000000000000000000000..25fca1f6ed7628d5503948f553324d7770a23a73
--- /dev/null
+++ b/tools/android/push_apps_to_background/push_apps_to_background.gyp
@@ -0,0 +1,21 @@
+# Copyright 2016 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.
+{
+  'targets': [
+    # GN: //tools/android/push_apps_to_background:push_apps_to_background_apk
+    {
+      'target_name': 'push_apps_to_background_apk',
+      'type': 'none',
+      'variables': {
+        'apk_name': 'PushAppsToBackground',
+        'java_in_dir': '.',
+        'resource_dir': 'res',
+        'android_manifest_path': 'AndroidManifest.xml',
+      },
+      'includes': [
+        '../../../build/java_apk.gypi',
+      ],
+    },
+  ],
+}