Revert " channelz: stage 4 - add security and socket option info" (#2124

)

Reverts #2098

Appengine will fail with the error below:
```
go-app-builder: Failed parsing input: parser: bad import "syscall" in google.golang.org/grpc/channelz/funcs.go from GOPATH
```

The root cause of it is in type_linux.go.
https://github.com/grpc/grpc-go/blob/629f6bc5e559f3a278d922c79f46678030797db3/channelz/types_linux.go#L21-L25

channelz/service/service.go

@@ -21,24 +21,17 @@ package service
 
 import (
 	"net"
-	"time"
 
 	"github.com/golang/protobuf/ptypes"
-	durpb "github.com/golang/protobuf/ptypes/duration"
 	wrpb "github.com/golang/protobuf/ptypes/wrappers"
 	"golang.org/x/net/context"
 	"google.golang.org/grpc"
 	"google.golang.org/grpc/channelz"
 	channelzgrpc "google.golang.org/grpc/channelz/grpc_channelz_v1"
 	channelzpb "google.golang.org/grpc/channelz/grpc_channelz_v1"
 	"google.golang.org/grpc/connectivity"
-	"google.golang.org/grpc/credentials"
 )
 
-func convertToPtypesDuration(sec int64, usec int64) *durpb.Duration {
-	return ptypes.DurationProto(time.Duration(sec*1e9 + usec*1e3))
-}
-
 // RegisterChannelzServiceToServer registers the channelz service to the given server.
 func RegisterChannelzServiceToServer(s *grpc.Server) {
 	channelzgrpc.RegisterChannelzServer(s, &serverImpl{})
@@ -135,26 +128,6 @@ func subChannelMetricToProto(cm *channelz.SubChannelMetric) *channelzpb.Subchann
 	return sc
 }
 
-func securityToProto(se credentials.ChannelzSecurityValue) *channelzpb.Security {
-	switch v := se.(type) {
-	case *credentials.TLSChannelzSecurityValue:
-		return &channelzpb.Security{Model: &channelzpb.Security_Tls_{Tls: &channelzpb.Security_Tls{
-			CipherSuite:       &channelzpb.Security_Tls_StandardName{StandardName: v.StandardName},
-			LocalCertificate:  v.LocalCertificate,
-			RemoteCertificate: v.RemoteCertificate,
-		}}}
-	case *credentials.OtherChannelzSecurityValue:
-		otherSecurity := &channelzpb.Security_OtherSecurity{
-			Name: v.Name,
-		}
-		if anyval, err := ptypes.MarshalAny(v.Value); err == nil {
-			otherSecurity.Value = anyval
-		}
-		return &channelzpb.Security{Model: &channelzpb.Security_Other{Other: otherSecurity}}
-	}
-	return nil
-}
-
 func addrToProto(a net.Addr) *channelzpb.Address {
 	switch a.Network() {
 	case "udp":
@@ -202,13 +175,6 @@ func socketMetricToProto(sm *channelz.SocketMetric) *channelzpb.Socket {
 	s.Data.LocalFlowControlWindow = &wrpb.Int64Value{Value: sm.SocketData.LocalFlowControlWindow}
 	s.Data.RemoteFlowControlWindow = &wrpb.Int64Value{Value: sm.SocketData.RemoteFlowControlWindow}
 
-	if sm.SocketData.SocketOptions != nil {
-		s.Data.Option = sockoptToProto(sm.SocketData.SocketOptions)
-	}
-	if sm.SocketData.Security != nil {
-		s.Security = securityToProto(sm.SocketData.Security)
-	}
-
 	if sm.SocketData.LocalAddr != nil {
 		s.Local = addrToProto(sm.SocketData.LocalAddr)
 	}