[Android] Change object types from AndroidCommands to DeviceUtils in build/android/.

build/android/host_heartbeat.py

Index: build/android/host_heartbeat.py
diff --git a/build/android/host_heartbeat.py b/build/android/host_heartbeat.py
index 6e011e234957e12a2719ee84c0d9969dc9f11882..429fca9ac1c96309e09e7dd04bbcc2401c4f74d0 100755
--- a/build/android/host_heartbeat.py
+++ b/build/android/host_heartbeat.py
@@ -13,6 +13,7 @@ import sys
 import time
 
 from pylib import android_commands
+from pylib.device import device_utils
 
 PULSE_PERIOD = 20
 
@@ -20,9 +21,9 @@ def main():
   while True:
     try:
       devices = android_commands.GetAttachedDevices()
-      for device in devices:
-        android_cmd = android_commands.AndroidCommands(device)
-        android_cmd.RunShellCommand('touch /sdcard/host_heartbeat')
+      for device_serial in devices:
+        device_utils.DeviceUtils(device_serial).RunShellCommand(
+            'touch /sdcard/host_heartbeat')
     except:
       # Keep the heatbeat running bypassing all errors.
       pass