Add baremetal _nostd variant am: e785f6b306 am: 08e87c0424

Original change: https://android-review.googlesource.com/c/platform/external/rust/crates/sec1/+/2770730

Change-Id: If819b77ae2eeba66c5b7aa546c7144a45bbf9bb4
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>