Migrate to cargo_embargo. am: 7f27bde8c5 am: 5db90f955f am: 43852746a3

Original change: https://android-review.googlesource.com/c/platform/external/rust/crates/prettyplease/+/2830430

Change-Id: Ia51e32ac71dfbbc3b4ce6cadbcc667fca2bd5856
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>