Migrate to cargo_embargo. am: 4fba66ab76

Original change: https://android-review.googlesource.com/c/platform/external/rust/crates/gdbstub/+/2841313

Change-Id: Iaa70940af669b4ded8f3e4125aa5c7f34e77ee42
Signed-off-by: Automerger Merge Worker <[email protected]>