QuickSettings: Remove vector drawable runtime processing.

Remove temporary harness responsible for creating enabled/disabled
versions of vectors at runtime.  Instead, pre-compute the necessary
states as separate files.

Normalize all qs icon names, cleanup obsolete pngs, and replace
the DND hangtag.

Bug:14133785
Change-Id: Ifb58635b832d25ca1de7e9f79cf8ec3503ea8cec