Mark apex-available am: 924a999ac5

Original change: https://android-review.googlesource.com/c/platform/external/rust/crates/grpcio-sys/+/3165980

Change-Id: Idda07fc17c7ac760dcfad17af8914fc2a80b4eb8
Signed-off-by: Automerger Merge Worker <[email protected]>