Make crate vendor available am: 31cf05e7c2

Original change: https://android-review.googlesource.com/c/platform/external/rust/crates/rand/+/2166849

Change-Id: I173ff443b509ef061ae9f7bc44fb02202a2127c8
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>