floss_patches: Change upstream remote name

upstream/main's remote name has changed from cros to cros-internal after
https://crrev.com/i/8221857.

BUG=b:412840445
TEST=floss_patches fix_upstream && floss_patches fix_upstream --continue

Change-Id: Idd372d1f4baf06c3bc91a9d2c51973d56911a776
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/bluetooth/+/6557328
Commit-Queue: Hsin-chen Chuang <chharry@google.com>
Tested-by: Hsin-chen Chuang <chharry@google.com>
Auto-Submit: Hsin-chen Chuang <chharry@google.com>
Reviewed-by: Dean Liao <deanliao@chromium.org>