[devil] Add system app replacement wrapper script.

devil/devil/android/tools/script_common.py

Index: devil/devil/android/tools/script_common.py
diff --git a/devil/devil/android/tools/script_common.py b/devil/devil/android/tools/script_common.py
index f91ad5eea0b41386f3fb64d11169092af216fed1..9a24bb3aaed1f52298a717d183fd4b79aefe35a2 100644
--- a/devil/devil/android/tools/script_common.py
+++ b/devil/devil/android/tools/script_common.py
@@ -7,7 +7,16 @@ from devil.android import device_errors
 from devil.android import device_utils
 
 
+def AddDeviceArguments(parser):
+  """Adds device and blacklist arguments to the provided parser."""
+  parser.add_argument(
+      '-d', '--device', dest='devices', action='append',
+      help='Serial number of the Android device to use. (default: use all)')
+  parser.add_argument('--blacklist-file', help='Device blacklist JSON file.')
+
+
 def GetDevices(requested_devices, blacklist_file):
+  """Gets a list of healthy devices matching the given parameters."""
   if not isinstance(blacklist_file, device_blacklist.Blacklist):
     blacklist_file = (device_blacklist.Blacklist(blacklist_file)
                       if blacklist_file