Migrate 25 crates to monorepo. am: d41918f53e

Original change: https://android-review.googlesource.com/c/platform/external/rust/crates/rand_core/+/3248757

Change-Id: Ide9f39af03518b2525b4e4a558438fd6787a4f71
Signed-off-by: Automerger Merge Worker <[email protected]>