Update gradle in vagrant to use jdk14 (#55130)

This commit updates the Java version used within vagrant tests by gradle
inside the VM to use JDK14.

closes #55044

Author: rjernst

buildSrc/src/main/java/org/elasticsearch/gradle/test/DistroTestPlugin.java

@@ -69,7 +69,7 @@
 import static org.elasticsearch.gradle.vagrant.VagrantMachine.convertWindowsPath;
 
 public class DistroTestPlugin implements Plugin<Project> {
-    private static final String GRADLE_JDK_VERSION = "13.0.1+9@cec27d702aa74d5a8630c65ae61e4305";
+    private static final String GRADLE_JDK_VERSION = "14+36@076bab302c7b4508975440c56f6cc26a";
     private static final String GRADLE_JDK_VENDOR = "openjdk";
 
     // all distributions used by distro tests. this is temporary until tests are per distribution