Add missing groupId for maven plugins we rely on.
Add missing groupId for maven plugins we rely on.

PiperOrigin-RevId: 468290651
Change-Id: I7918447a5a09247063a9d760c16dd8d4e41e2300

GoogleCloudPlatform/appengine-java-standard,GoogleCloudPlatform/appengine-java-standard,GoogleCloudPlatform/appengine-java-standard,GoogleCloudPlatform/appengine-java-standard