Make proc-macro-nested available to product and vendor am: 7ca4181c61 am: d34f330c06 am: 272b883bc2

Original change: https://android-review.googlesource.com/c/platform/external/rust/crates/proc-macro-nested/+/2476454

Change-Id: I3fbfea2005f90a2e846c594a9191ed8932f042b9
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>