Fix package prefix for resources

When i was importing metrics-api, i saw the following exception in the log.,
 INFO - s.impl.ProjectManagerComponent - sync roots
java.lang.Throwable: sync roots
    at com.intellij.openapi.roots.impl.ProjectRootManagerComponent.doSynchronizeRoots(ProjectRootManagerComponent.java:309)
    at com.intellij.openapi.roots.impl.ProjectRootManagerImpl.fireRootsChanged(ProjectRootManagerImpl.java:425)
    at com.intellij.openapi.roots.impl.ProjectRootManagerImpl.access$100(ProjectRootManagerImpl.java:56)
    at

Testing Done:
yes

Reviewed at https://rbcommons.com/s/twitter/r/1322/