[Android]: Only kill 'adb' during device status check, not all commands with adb in command line.

This was causing the perf tests to fail since the bb_device_steps_internal.py
had '--adb-root' as an argument and so was being accidentially killed during
the device status check.

BUG=312285

Review URL: https://codereview.chromium.org/56063002

git-svn-id: http://src.chromium.org/svn/trunk/src/build@232610 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

android/buildbot/bb_device_status_check.py

@@ -256,7 +256,7 @@ def RestartUsb():
 def KillAllAdb():
   def GetAllAdb():
     for p in psutil.process_iter():
-      if 'adb' in p.name or 'adb' in ' '.join(p.cmdline):
+      if 'adb' in p.name:
         yield p
 
   for sig in [signal.SIGTERM, signal.SIGQUIT, signal.SIGKILL]: