message: build: Update protobuf
  In order to compile envoy for iOS we need this commit
  from protobuf. This also includes the previous commits that required us
  to use a non-release version.
diff: @@ -197,15 +197,9 @@ REPOSITORY_LOCATIONS = dict(
  urls = ["https://github.com/google/googletest/archive/eb9225ce361affe561592e0912320b9db84985d0.tar.gz"],
  ),
  com_google_protobuf = dict(
  - sha256 = "46f1da3a6a6db66dd240cf95a5553198f7c6e98e6ac942fceb8a1cf03291d96e",
  - strip_prefix = "protobuf-7492b5681231c79f0265793fa57dc780ae2481d6",
  - # TODO(htuch): Switch back to released versions for protobuf when a release > 3.6.0 happens
  - # that includes:
  - # - https://github.com/protocolbuffers/protobuf/commit/f35669b8d3f46f7f1236bd21f14d744bba251e60
  - # - https://github.com/protocolbuffers/protobuf/commit/6a4fec616ec4b20f54d5fb530808b855cb664390
  - # - https://github.com/protocolbuffers/protobuf/commit/fa252ec2a54acb24ddc87d48fed1ecfd458445fd
  - # - https://github.com/protocolbuffers/protobuf/commit/7492b5681231c79f0265793fa57dc780ae2481d6
  - urls = ["https://github.com/protocolbuffers/protobuf/archive/7492b5681231c79f0265793fa57dc780ae2481d6.tar.gz"],
  + sha256 = "3e933375ecc58d01e52705479b82f155aea2d02cc55d833f8773213e74f88363",
  + strip_prefix = "protobuf-3.7.0",
  + urls = ["https://github.com/protocolbuffers/protobuf/releases/download/v3.7.0/protobuf-all-3.7.0.tar.gz"],
  ),
  grpc_httpjson_transcoding = dict(
  sha256 = "dedd76b0169eb8c72e479529301a1d9b914a4ccb4d2b5ddb4ebe92d63a7b2152",
  