Finish switching to decorators.idempotent_id

Most modules are switched to using decorators.idempotent_id and
this patch covers the remaining and removes the old decorator check.

NOTE: The old decorator test.idempotent_id is still necessary to be
      used on the other projects.

Change-Id: Ice7f593fbc109863eba11402c2f3af75fc6ab9a1
Closes-Bug: #1616913
8 files changed