Integer optionalOr(@Nonnull Integer i, int defaults) {
        return i == 0 ? defaults : i;
    }
Check if a given non-null Integer instance is "missing" according to ProtoBuf's missing field
rules. If the Integer is missing (i.e. if it has a zero-value), the given default value will
be returned. Otherwise, the Integer itself will be returned.

@param i the input Integer
@param defaults the default value for the Integer
@return 'i' if it is not a zero-value according to ProtoBuf rules; 'defaults' otherwise
grpc-server/src/main/java/com/netflix/conductor/grpc/server/service/GRPCHelper.java