Migrate 25 crates to monorepo. am: b242094abf

Original change: https://android-review.googlesource.com/c/platform/external/rust/crates/maybe-async/+/3246595

Change-Id: I626bb58f15b8840c4a49472be5e534175b9166c3
Signed-off-by: Automerger Merge Worker <[email protected]>