Merge "rust: Mark DeathRecipient Send and Sync" am: 593991bfd9

Original change: https://android-review.googlesource.com/c/platform/frameworks/native/+/2054944

Change-Id: I11f610964914ccabe2be14b522073d4c5a5ad979
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>