Add baremetal _nostd variant am: e785f6b306 am: 08e87c0424 am: bc68e33d53 am: 7058f50f98

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

Change-Id: I56a6bc2c733ffb5cd0a71d0b37221375e748896e
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>