Only run Checkstyle for JDK11+ to avoid build issues on JDK8

Author: coheigea

pom.xml

@@ -325,11 +325,6 @@
         <artifactId>maven-source-plugin</artifactId>
       </plugin>
 
-      <plugin>
-        <groupId>org.apache.maven.plugins</groupId>
-        <artifactId>maven-checkstyle-plugin</artifactId>
-      </plugin>
-
       <plugin>
         <groupId>org.apache.maven.plugins</groupId>
         <artifactId>maven-site-plugin</artifactId>
@@ -761,6 +756,20 @@
   </reporting>
 
   <profiles>
+    <profile>
+      <id>checkstyle-activation</id>
+      <activation>
+        <jdk>[11,)</jdk>
+      </activation>
+      <build>
+        <plugins>
+          <plugin>
+            <groupId>org.apache.maven.plugins</groupId>
+            <artifactId>maven-checkstyle-plugin</artifactId>
+          </plugin>
+        </plugins>
+      </build>
+    </profile>
     <profile>
       <id>apache-release</id>
       <build>