overlay: remove screenOnAnimation

It's not used.

Change-Id: I88658d8c3a4a228b7343b61f14347372c7f4bcbf
config_screenOnAnimation is gone in cm-10.1
Merge branch 'cm-10.1' of bitbucket.org:CyanogenMod-Atrix/android_device_motorola_olympus into cm-10.1