SystemUI: Reinflate on theme change

Summary:
Reflect the updated assets immediately once the config_changed
notification happens

Change-Id: I480a719fbdd45875277871af39ce65849918ec0a

Test Plan: build, test, merge

Reviewers: synergy, anders3408, jriordan001, raymanfx, donald.munn

Reviewed By: synergy

Differential Revision: http://review.codefirex.com/D168