TouchInterceptor: Fixed image cache problems

Fixes the problem shown in this video:
http://youtu.be/piqHych4nJY

Original commit:
https://github.com/CyanogenMod/android_packages_apps_Settings/commit/7c9
652ab5fcebaaa573d128951759d1ceaf4acaf

Signed-off-by: htchoi1995 <htchoi1995@gmail.com>