[Telemetry] Refactor common Android cleanup functions.

build/android/pylib/android_commands.py

 # Copyright (c) 2012 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.
 
 """Provides an interface to communicate with the device via the adb command.
 
 Assumes adb binary is currently on system path.
 """
 
 import collections
@@ skipping 484 matching lines @@
     return ret
 
   def StartAdbServer(self):
     """Start adb server."""
     adb_cmd = ['taskset', '-c', '0', constants.ADB_PATH, 'start-server']
     ret = cmd_helper.RunCmd(adb_cmd)
     retry = 0
     while retry < 3:
       ret = cmd_helper.RunCmd(['pgrep', 'adb'])
       if ret == 0:
-        # pgrep fonud adb, start-server succeeded.
+        # pgrep found adb, start-server succeeded.
+        # Waiting for device to reconnect before returning success.
+        self._adb.SendCommand('wait-for-device')
         return 0
       retry += 1
       time.sleep(retry)
     return ret
 
   def WaitForSystemBootCompleted(self, wait_time):
     """Waits for targeted system's boot_completed flag to be set.
 
     Args:
       wait_time: time in seconds to wait
@@ skipping 1187 matching lines @@
   """
   def __init__(self, output):
     self._output = output
 
   def write(self, data):
     data = data.replace('\r\r\n', '\n')
     self._output.write(data)
 
   def flush(self):
     self._output.flush()