Always invoke adb through function

Change-Id: I5956b3cf3ead3fdbf6399748359b324bc76001a0
diff --git a/deploy.py b/deploy.py
index 590e150..0db59e0 100755
--- a/deploy.py
+++ b/deploy.py
@@ -115,9 +115,7 @@
         uninstall_apk(serial, app, prebuilts_dir)
 
     # Copy the scenarios
-    ret = subprocess.run(['adb', '-s', serial, 'push', scenarios_dir,
-            '/sdcard/viser'], stdout=subprocess.PIPE, stderr=subprocess.PIPE,
-            universal_newlines=True)
+    ret = adb('push', scenarios_dir, '/sdcard/viser', serial=serial)
     if 0 < ret.returncode:
         print('Could not push the scenarios, error was: {}'.format(ret.stderr),
                 file=sys.stderr)
@@ -125,9 +123,7 @@
         print('Scenarios pushed.')
 
     # Copy the scenarios data
-    ret = subprocess.run(['adb', '-s', serial, 'push', data_dir,
-            '/sdcard/viser/data'], stdout=subprocess.PIPE,
-            stderr=subprocess.PIPE, universal_newlines=True)
+    ret = adb('push', data_dir, '/sdcard/viser/data', serial=serial)
     if 0 < ret.returncode:
         print('Could not push the scenarios data, error was: {}'.format(ret.stderr),
                 file=sys.stderr)
@@ -246,10 +242,9 @@
         prepare_dut(serial, '../scenarios', '../scenarios-data', PREBUILTS_PATH)
 
         # Start the viser app
-        ret = subprocess.run(['adb', '-s', serial, 'shell', 'monkey', '-p',
-                'com.lunarlabs.panda', '-c', 'android.intent.category.LAUNCHER',
-                '1'], stdout=subprocess.PIPE, stderr=subprocess.PIPE,
-                universal_newlines=True)
+        ret = adb(
+                'shell', 'monkey', '-p', 'com.lunarlabs.panda', '-c',
+                'android.intent.category.LAUNCHER', '1', serial=serial)
         if 0 < ret.returncode:
             print('Could not start the viser app, error was: {}'.format(app,
                     ret.stderr), file=sys.stderr)