Java compilation error -- only with Ubuntu+openjdk

I have some Java code that compiles on my Mac, but fails to compile on my Ubuntu machine. Specifically, when using the static of method of List, I get the error:

error: cannot find symbol
        List<String> list2 = List.of("cat", "dog");
                                 ^
  symbol:   method of(String,String)
  location: interface List
1 error

I thought perhaps this was an issue with the Java version. Sure enough, it was using only Java 8. However, I subsequently upgraded my Ubuntu machine to use Java 11 using OpenJDK, but I still get the same issue.

The output I get from running java -version on the Ubuntu machine is:

openjdk version "11.0.1" 2018-10-16
OpenJDK Runtime Environment (build 11.0.1+13-Ubuntu-3ubuntu116.04ppa1)
OpenJDK 64-Bit Server VM (build 11.0.1+13-Ubuntu-3ubuntu116.04ppa1, mixed mode, sharing)

The output I get from running java -version on the Mac machine is:

java version "10.0.1" 2018-04-17
Java(TM) SE Runtime Environment 18.3 (build 10.0.1+10)
Java HotSpot(TM) 64-Bit Server VM 18.3 (build 10.0.1+10, mixed mode)

For compilation, I am using Gradle version 5.2.1. I am using the Gradle wrapper, so both machines are using the same version of Gradle.

Here is the file that does not compile properly.

package mypackage;

import java.util.List;
import java.util.ArrayList;

public class App {

    public static void main(String[] args) {
        // No errors on both MacOS and Ubuntu
        List<String> list1 = new ArrayList<>();
        list1.add("cat");
        System.out.println(list1);

        // Fails to compile on Ubuntu
        List<String> list2 = List.of("cat", "dog");
        System.out.println(list2);
    }
}