Deprecate --archive_dir flag for devserver.

Remove archive_dir, since dev_server_wrapper currently passes in the
default.

If archive_dir function is needed, use the static_dir flag.

BUG=chromium:261775
TEST=None

Change-Id: I9e111d1c8604ccecc5ee3954d9fd2f0fde70637f
Reviewed-on: https://gerrit.chromium.org/gerrit/65606
Reviewed-by: Don Garrett <dgarrett@chromium.org>
Reviewed-by: Joy Chen <joychen@chromium.org>
Tested-by: Joy Chen <joychen@chromium.org>
Commit-Queue: Joy Chen <joychen@chromium.org>
diff --git a/lib/dev_server_wrapper.py b/lib/dev_server_wrapper.py
index d118d1e..8f0f270 100644
--- a/lib/dev_server_wrapper.py
+++ b/lib/dev_server_wrapper.py
@@ -61,7 +61,7 @@
   def run(self):
     # Kill previous running instance of devserver if it exists.
     self.Stop()
-    cmd = ['start_devserver', '--archive_dir=./static']
+    cmd = ['start_devserver']
     cros_build_lib.SudoRunCommand(cmd, enter_chroot=True, print_cmd=False,
                                   log_stdout_to_file=self._log_filename,
                                   combine_stdout_stderr=True,