Do not dump the --config argument.

When generating a config file from a commandline, cargo2android.py
should not dump the --config argument, as the point of the dump is to
generate a config file to use.  This would not normally matter, but it
could help in scripts.

Test: Run and do not see --config in the dumped file.
Change-Id: Idc2911ba674e67272c9cf836c89607e10ca0dddd
diff --git a/scripts/cargo2android.py b/scripts/cargo2android.py
index fef1d51..3cc928b 100755
--- a/scripts/cargo2android.py
+++ b/scripts/cargo2android.py
@@ -1752,8 +1752,8 @@
   # Also filter certain "temporary" arguments.
   non_default_args = {}
   for arg in args_dict:
-    if args_dict[arg] != parser.get_default(
-        arg) and arg != 'dump_config_and_exit' and arg != 'no_test_mapping':
+    if (args_dict[arg] != parser.get_default(arg) and arg != 'dump_config_and_exit'
+        and arg != 'no_test_mapping' and arg != 'config'):
       non_default_args[arg.replace('_', '-')] = args_dict[arg]
   # Write to the specified file.
   with open(args.dump_config_and_exit, 'w') as f: