Upgrade grpcio-compiler to 0.12.1

Cloned from aosp/2631289
Originally generated with:
tools/external_updater/updater.sh update rust/crates/grpcio-compiler

Bug: 266055490
Test: mm, presubmit
Change-Id: I95dbdb867382f5a8009a8bf8f96a444787f9d885
9 files changed