quickboot: Disable quickboot by default

* We probably don't want to enable this by default on devices that have
  it because it is confusing to users attempting to shut down their
  phones.

Change-Id: I80eb946f93509cb3b32f6c790611597921b9c54a
Cleanup theme assets when done with them

Before this patch if phone was left on long enough it would reboot
when a theme was applied due to files being left open.

Change-Id: I4c242249fcf6e8097789c3dd6690104296485784