The `make_grpcio_tools.py` rube-goldberg machinery relies on
`bazel` to extract the list of files required to compile the
`grpcio-tools` package that are provided by the `protobuf`
submodule. In order to ensure that list is up to date,
`check_grpcio_tools.py` sanity check does the same `bazel`
query, and checks the full contents against the already
existing list in the repository. This has the downside of
requiring `bazel` to run that particular check at sanity test
time, and flakiness has been seen there.
This commit changes the code generation process to include
the git hash of the submodule at the time `make_grpcio_tools.py`
is invoked and stores it in the generated file and instead of
doing the whole process at test time, the `check_grpcio_tools.py`
sanity test simply checks the submodule version at test time
and verifies it against the version included in the file by
`make_grpcio_tools.py` thus removing the `bazel` dependency
at test time and increasing test robustness and speed.
9b4315682b