Revert "Move <reportPlugins> to <reporting><plugins> (#3524)" (#3806)

This reverts commit c04cd63.

Author: chingor13

java-storage-nio/google-cloud-nio-examples/pom.xml

@@ -28,7 +28,6 @@
       <plugin>
         <groupId>org.codehaus.mojo</groupId>
         <artifactId>exec-maven-plugin</artifactId>
-        <version>1.6.0</version>
         <configuration>
           <skip>false</skip>
         </configuration>

java-storage-nio/google-cloud-nio/pom.xml

@@ -74,7 +74,6 @@
       <plugin>
         <groupId>org.codehaus.mojo</groupId>
         <artifactId>exec-maven-plugin</artifactId>
-        <version>1.6.0</version>
         <configuration>
           <skip>false</skip>
         </configuration>