[FAB-5978] Protolator support for Capabilities msg

This CR defines the metadata necessary for the configtxlator /
protolator to understand the new Capabilities type.  It also adds an
additional check to the protolator to not try to deeply marshal beyond
non-string map fields which was discovered while attempting to support
this new message.

Change-Id: I34aecb30ad7bdf7a99f2e8db7e203be26a7488e8
Signed-off-by: Jason Yellick <jyellick@us.ibm.com>

Author: Jason Yellick

common/tools/protolator/nested.go

@@ -65,7 +65,7 @@ func (nff nestedFieldFactory) NewProtoField(msg proto.Message, fieldName string,
 type nestedMapFieldFactory struct{}
 
 func (nmff nestedMapFieldFactory) Handles(msg proto.Message, fieldName string, fieldType reflect.Type, fieldValue reflect.Value) bool {
-	return fieldType.Kind() == reflect.Map && fieldType.Elem().AssignableTo(protoMsgType) && !fieldType.Elem().AssignableTo(timestampType)
+	return fieldType.Kind() == reflect.Map && fieldType.Elem().AssignableTo(protoMsgType) && !fieldType.Elem().AssignableTo(timestampType) && fieldType.Key().Kind() == reflect.String
 }
 
 func (nmff nestedMapFieldFactory) NewProtoField(msg proto.Message, fieldName string, fieldType reflect.Type, fieldValue reflect.Value) (protoField, error) {

protos/peer/configuration.go

@@ -99,6 +99,8 @@ func (ccv *DynamicApplicationConfigValue) VariablyOpaqueFieldProto(name string)
 		return nil, fmt.Errorf("Not a marshaled field: %s", name)
 	}
 	switch ccv.name {
+	case "Capabilities":
+		return &common.Capabilities{}, nil
 	default:
 		return nil, fmt.Errorf("Unknown Application ConfigValue name: %s", ccv.name)
 	}