Prefer modern plugins block

Author: chadlwilson

build.gradle

@@ -14,7 +14,9 @@
  * limitations under the License.
  */
 
-apply plugin: 'java'
+plugins {
+  id 'java'
+}
 apply from: "https://raw.githubusercontent.com/gocd/gocd-plugin-gradle-task-helpers/master/helper.gradle?_=${(int) (new Date().toInstant().epochSecond / 60)}"
 
 gocdPlugin {