Generate a .bat file for running tests in a rust_unit_test_group

When targetting Windows, generate a .bat file instead of a bash script.

Bug: 1271215
Change-Id: I682614081af8a30de10ae95f496373a665c078c8
Cq-Include-Trybots: luci.chromium.try:android-rust-arm32-rel,android-rust-arm64-dbg,android-rust-arm64-rel,linux-rust-x64-dbg,linux-rust-x64-rel
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4436654
Reviewed-by: Robert Sesek <rsesek@chromium.org>
Reviewed-by: Ɓukasz Anforowicz <lukasza@chromium.org>
Commit-Queue: danakj <danakj@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1132123}
NOKEYCHECK=True
GitOrigin-RevId: 89813763da19f98ffd82e1701b004a95a19a80f1
4 files changed