Use hyphen rather than underscore in cargo2android.json. am: f08f333d7c

Original change: https://android-review.googlesource.com/c/platform/external/rust/crates/grpcio-sys/+/2822012

Change-Id: I0833232b77ebd35c1e8489f18e06dc7f70ffabdf
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>