[Android] Don't use a device blacklist if one isn't provided.

build/android/update_verification.py

Index: build/android/update_verification.py
diff --git a/build/android/update_verification.py b/build/android/update_verification.py
index c73a06156fb8ba1bfe2da3ae1fe5d33604aa64d0..b25ea493098a4fdbeaa421019e0a90cb3ab79b78 100755
--- a/build/android/update_verification.py
+++ b/build/android/update_verification.py
@@ -90,10 +90,9 @@ def main():
   args = parser.parse_args()
   run_tests_helper.SetLogLevel(args.verbose)
 
-  if args.blacklist_file:
-    blacklist = device_blacklist.Blacklist(args.blacklist_file)
-  else:
-    blacklist = None
+  blacklist = (device_blacklist.Blacklist(args.blacklist_file)
+               if args.blacklist_file
+               else None)
 
   devices = device_utils.DeviceUtils.HealthyDevices(blacklist)
   if not devices: