Initial import of grpcio-compiler. am: 166a6f003e

Original change: https://android-review.googlesource.com/c/platform/external/rust/crates/grpcio-compiler/+/1486596

Change-Id: I617616d0656fafb2d4e513f297f1ba6fc1762225
tree: e327cafa4b052576b6094ec8f789657193c83767
  1. src/
  2. .cargo_vcs_info.json
  3. Cargo.lock
  4. Cargo.toml
  5. Cargo.toml.orig