Migrate 3 crates to monorepo. am: 928b7df099

Original change: https://android-review.googlesource.com/c/platform/external/rust/crates/maplit/+/3410377

Change-Id: I9389f122f4acb8ba8198378b8573dc7dfe5a9856
Signed-off-by: Automerger Merge Worker <[email protected]>