dependencies: update protobuf to 3.8.0 (#7510)
dependencies: update protobuf to 3.8.0 (#7510)

In addition to updating protobuf to 3.8.0, this PR also

Removes old protobuf patch now included in 3.8.0
- Patches protocolbuffers/protobuf#6333 that fixes a UBSAN error in the protobuf library.
- Patches protobuf's BUILD to depend on foreign_cc zlib

Risk level: low/medium
Testing: bazel test //test/...

Signed-off-by: Asra Ali <asraa@google.com>

Mirrored from https://github.com/envoyproxy/envoy @ 8246167b9d238797cbc6c03dccc9e3921c37617d

lyft/envoy-api,lyft/envoy-api,lyft/envoy-api