Merge "Revert "Turn off adb on user builds."" am: 7be6751e

      else:

        val = val + ",adb"

      prop_list.put("persist.sys.usb.config", val)

  # UsbDeviceManager expects a value here.  If it doesn't get it, it will

  # default to "adb". That might not the right policy there, but it's better

  # to be explicit.

  if not prop_list.get_value("persist.sys.usb.config"):

    prop_list.put("persist.sys.usb.config", "none")

def validate_grf_props(prop_list, sdk_version):

  """Validate GRF properties if exist.