Add missing storage ids to work with new Panels ACL.

Upgrading task handlers from Panels 7.x-3.5 or older to Panels 7.x-3.6 and newer:

- You must specify a storage type for any panels display using your custom task handler.
For examples, see panels_update_7306.

- When creating whatever stores the panel, a storage id and storage type must be defined.
See panels_mini.module for examples inside panels_mini_save and panels_mini_panels_cache_get.

- A display access plugin must be defined.
See panels_mini/plugins/panels_storage/panels_mini.inc for an example plugin.