When testing according to the documentation, I encountered a grpc-message: unknown method GetErrResp for service helloworld.Greeter error.

The GetErrResp method needs to be added to ensure a smooth presentation according to the documentation

refer to: https://github.com/apache/apisix/pull/7639/files#diff-43ceb61b9cc69a6a375b12350280348f412e06bbb231b9d963b8655a8bd9ddb5R98

Now the release package has only amd64 version, without arm64 version, it is impossible to test APISIX related functions in arm64 environment.
ping @nic-chen @membphis

Reproduction:

1. cd path_to_grpc_server_example
2. go run main.go

Errors message:
grpc_server_example git:(master) go run main.go
2022/06/03 22:54:50 credentials.NewServerTLSFromFile err: open ../t/cert/apisix.crt: no such file or directory
exit status 1

Cause of problem: