patch_sync: Fix for Rust 1.55 compat, cli patch

On chrotomation, we still use Rust 1.55.
Rust 1.55 does not have the "from" implementation for arrays,
so we must build the BTrees by hand.

Additionally, this removes the requirement for having the
review strings be set.

BUG=b:209493133
TEST=cargo check

Change-Id: I6bc16e96cd56775c8c80667395f3dc3fb4857356
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/toolchain-utils/+/3403387
Tested-by: Jordan Abrahams-Whitehead <ajordanr@google.com>
Reviewed-by: George Burgess <gbiv@chromium.org>
Commit-Queue: Jordan Abrahams-Whitehead <ajordanr@google.com>
2 files changed