Migrate to cargo_embargo. am: 6fd24aae90 am: b4f83899c6

Original change: https://android-review.googlesource.com/c/platform/external/rust/crates/either/+/2796179

Change-Id: I6e96ad4bb14adec184f2b2c9cc96711980cf63b0
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>