use grpc-proto bazel_dep instead of http_archive

[mmorel-35]

[mmorel-35]

@ejona86, @keith , Would you like to review this ?

[mmorel-35]

Something is wrong with Linux and apt . Anyone can do something? Retry or something else ?

[ejona86]

You don't need to worry about it. CentOS died on July 1st, so we need to swap to something else. But it is unrelated.

Earlier Macos failed (grpc-servlet test flake), and I was waiting for it to re-run. Looks like it is passing now. Now we just need a second review.