scripts: upload_prebuilts: sync remote SDK file

Oops, I accidentally merged a bug one month ago, and now the remote
SDK file is a month stale. See attached bug for details. The correct
behavior is to sync the remote file unless we specify not to.

Also added test coverage.

BUG=b:280879394
TEST=./run_tests

Change-Id: I3c91c70a1540e4129c0992e09d9289f8ea0c3087
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/chromite/+/4505917
Auto-Submit: Greg Edelston <gredelston@google.com>
Tested-by: Greg Edelston <gredelston@google.com>
Reviewed-by: Jack Rosenthal <jrosenth@chromium.org>
Commit-Queue: Jack Rosenthal <jrosenth@chromium.org>
diff --git a/scripts/upload_prebuilts.py b/scripts/upload_prebuilts.py
index 1c9a7b2..fc80dc3 100644
--- a/scripts/upload_prebuilts.py
+++ b/scripts/upload_prebuilts.py
@@ -26,7 +26,7 @@
 import os
 from pathlib import Path
 import tempfile
-from typing import Optional
+from typing import Optional, Tuple
 
 from chromite.cbuildbot import cbuildbot_alerts
 from chromite.cbuildbot import commands
@@ -813,7 +813,7 @@
         namespace.slave_targets[-1].profile = values
 
 
-def ParseOptions(argv):
+def ParseOptions(argv) -> Tuple[argparse.Namespace, Optional[BuildTarget]]:
     """Returns options given by the user and the target specified.
 
     Args:
@@ -931,6 +931,7 @@
     parser.add_argument(
         "--sync-remote-latest-sdk-file",
         action="store_true",
+        default=True,
         help="Sync the remote latest SDK file on GS://. (Default)",
     )
     parser.add_argument(