[telemetry] Install PushAppsToBackground apk

telemetry/telemetry/core/android_platform.py

 # Copyright 2014 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.
 
 from telemetry.core import android_action_runner
 from telemetry.core import platform
 from telemetry.internal.app import android_app
 from telemetry.internal.backends import android_app_backend
 
 
 class AndroidPlatform(platform.Platform):
 
   def __init__(self, platform_backend):
     super(AndroidPlatform, self).__init__(platform_backend)
     self._android_action_runner = android_action_runner.AndroidActionRunner(
         platform_backend)
 
+  def Initialize(self):
+    self._platform_backend.EnsureBackgroundApkInstalled()
+
   @property
   def android_action_runner(self):
     return self._android_action_runner
 
   @property
   def system_ui(self):
     """Returns an AppUi object to interact with Android's system UI.
 
     See devil.android.app_ui for the documentation of the API provided.
     """
@@ skipping 20 matching lines @@
           object may be used to access them.
 
     Returns:
       A reference to the android_app launched.
     """
     self._platform_backend.DismissCrashDialogIfNeeded()
     app_backend = android_app_backend.AndroidAppBackend(
         self._platform_backend, start_intent, is_app_ready_predicate,
         app_has_webviews)
     return android_app.AndroidApp(app_backend, self._platform_backend)