[android] Try killing adb server if no devices found

build/android/adb_install_apk.py

Index: build/android/adb_install_apk.py
diff --git a/build/android/adb_install_apk.py b/build/android/adb_install_apk.py
index adad48bdef84a445d58e3f443017b979302706d4..e57e0b375efda06c63948df8f5a445da6fa1eda3 100755
--- a/build/android/adb_install_apk.py
+++ b/build/android/adb_install_apk.py
@@ -10,6 +10,7 @@ import multiprocessing
 import optparse
 import os
 import sys
+import time
 
 from pylib import android_commands
 from pylib import constants
@@ -58,7 +59,20 @@ def main(argv):
   if len(args) > 1:
     raise Exception('Error: Unknown argument:', args[1:])
 
-  devices = android_commands.GetAttachedDevices()
+  retry_times = 5
+  retry_interval = 10
+  while retry_times > 0:
+    devices = android_commands.GetAttachedDevices()
+    if not devices:
+      print 'No connected devices found, '\
+            'kill adb server and retry in %d seconds...' % retry_interval
+      android_commands.AndroidCommands().KillAdbServer()
+      time.sleep(retry_interval)
+      retry_interval *= 2
+      retry_times -= 1
+    else:
+      break
+
   if not devices:
     raise Exception('Error: no connected devices')